What Is a VRML File

VRML acts in many ways, the same way HTML files can produce many different effects on the screen. A VRML file is composed of a series of text commands that are interpreted by the VRML browser and displayed on the screen, but the file's objects are all three-dimensional. This content is referred to as a world or scene. In HTML, you place text and images on the screen using tags. Similar to tags, VRML files have nodes that define 3D objects such as cubes, spheres, and other shapes in a real 3D coordinate system. With the browser, you can navigate around these worlds at your own pleasure, examining the world from whatever angle you want. Basic worlds can be enhanced by adding lights, colors, textures, and motion to the scene. To navigate around the scene, you move the mouse-the scene changes in real-time. So, by moving the mouse forward, the objects in the world become larger, as if you're approaching them. If you pull the mouse back, the scene recedes. If you click and drag the right mouse button, the entire scene rotates around its center. How VRML Is Similar to HTML Just as HTML is designed purely for document formatting, VRML is designed for 3D VR scenes. Most of the rules of creating Web pages also apply to creating 3D worlds. If you create a 3D scene, make sure it's interesting and offers the user something to do. Similarly, if you create a plain HTML page with no headings-just pure text-it too will be boring, ensuring that visitors don't return. Say you create a Web page that looks absolutely stunning with lots of graphics, but it takes twenty minutes to download-how often do you expect people to visit? You must apply the same rules to creating VRML worlds that you do to creating Web pages. By its nature, VRML creates larger files than HTML does, but you can keep the file sizes to a reasonable level. Limiting the use of large images (textures), sticking to using color only, and using simple primitives are some techniques "Tricks to Optimize Your VRML Worlds for the Web," covers some of the common methods for optimizing your creations to keep people coming back. An outstanding Web page can be put together in a couple of hours, if you have all your resources ready to go. Because VRML is more complex, it takes more time, even when you're using a GUI construction tool. However, it always pays to spend some time planning what your new world will look like in all three dimensions. Once you add in that third dimension, VRML starts to diverge from its 2D "relation." HTML pages can be viewed in only one way, defined by the page writer, but users can explore VR worlds by looking at them in whatever way they like. The similarities between the two technologies stretch further than just the method of creating them. Many HTML pages are designed much as magazine pages are, with lots of pretty graphics and links, and some cutting-edge pages seek to break this mold by stretching technology to do something unique. VRML is no different. A vast majority of VR worlds use traditional earthbound paradigms, such as the shop and art gallery examples presented in this book. However, a few stretch the limits as they seek to explore the possibilites of virtual reality. VRML offers a whole system for artists to create with, but HTML only allows them to display one of their creations. When creating a Web page, you can do it in several ways. You could use a plug-in to common word processing packages (Internet Assistant for MS Word), a standalone application (Sausage Software's Hotdog or MS FrontPage), or the text editor of your choice. Equivalents exist for VRML world builders. You can export files from packages like AutoCAD and 3D Studio, use standalone dedicated applications like VRealm Builder, or use a text editor. However, with the pace at which VRML is developing, you should get familiar with a text editor. The best worlds are still created by hand, particularly when it comes to creating behaviors in VRML 2.0. Working in Three Dimensions One of the most important differences between VRML and HTML is that with VRML you have a whole extra dimension to worry about. This added dimension gives the visitor to your VRML world the chance to go inside, behind, and around your scene. This can be used to your advantage, but it also presents some difficulties. The next section examines some of the advantages and disadvantages to working with this third dimension. Advantages First, you have more freedom. All those 3D effects you've been producing in earlier sections of this book can now be done in real-time. Instead of just looking at a picture of a car, you can walk around it, kicking virtual tires if you like. The images and animations created up until now are all canned. You can play the animation a thousand times and it always looks the same. A VRML world, on the other hand, presents infinite ways to view the animation, all at the viewer's discretion. VRML has a second advantage: control. Users can view the scene from any angle (if they can effectively navigate), so they aren't stuck viewing the same image every time. A third advantage to VRML is the ability to obscure items. By using the third dimension, you can hide items behind other items, something tricky to do on HTML pages. This enables you play some interesting hide-and-seek games. Perhaps the greatest advantage to using the third dimension is the realism you achieve. Moving a user through an architectural structure gives them a much better feeling of spatial relationships for the building than pictures do. One of the intended uses of VRML is in the remote visualization of data. This might take the form of a VR world that mimics the environment a remote-controlled vehicle is operating in, or it might even act as mock-ups of designs. Now, there are several other languages and file formats that could do this, but VRML was born with the Internet firmly in mind. Anyone should be able to view any VRML world without needing proprietary software. VRML has the same benefits for users in the 3D arena that HTML has for people working in 2D environments and document publishing. Disadvantages Probably the most challenging aspect of working in 3D is trying to manipulate a 3D model in 2D. Input devices like the mouse are two-dimensional, so moving them in 3D can be difficult. Even with 3D-based interfaces like Caligari's Pioneer, or the split view approach of 3D Studio, it's still difficult to keep track of exactly how things look until you get to see them in the final environment. Not only are computer input devices 2D, so are output devices, such as the monitor. Moving around the world helps the viewer understand the relative positions of objects, but it's still difficult to determine depth on 2D monitors. In the future, head-mounted displays will help. Head-mounted displays are worn like glasses; the scene changes as you move your head. To see the object behind you, you turn around. The main disadvantage to working with real-time 3D is the computing time involved. The poor little processor really has to work hard to calculate how the scene looks as you move. The more complex the scene, the more it taxes the processor. Because of the huge calculations involved, the details of VRML worlds are purposely kept simple. You may have noticed that the images in the first half of the book don't really compare with images created in a VRML world.The scenes in the first half are drawn only once, but in VRML, the world may be redrawn as often as 30 times a second. Complex scenes take longer to draw, so to keep users happy, the world is much less detailed. Complex pre-rendered animation can take all night to produce just a single frame of the animation, but when the animation's complete, you can play it as fast as you want. VRML worlds have less than a second to compute and render the scene before your eyes detect that the motion isn't fluid. So until processors get much more powerful, you're stuck with the simple-looking worlds. ...

JAMHARI BIN RAFEAL...TAWAU...SABAH....

For Further Information about VRML Please Visit This Site

WHAT IS TCP/IP

It is a software-based communications protocol used in networking. Although the name TCP/IP implies that the entire scope of the product is a combination of two protocols—Transmission Control Protocol and Internet Protocol—the term TCP/IP refers not to a single entity combining two protocols, but a larger set of software programs that provides network services such as remote logins, remote file transfers, and electronic mail. TCP/IP provides a method for transferring information from one machine to another. A communications protocol should handle errors in transmission, manage the routing and delivery of data, and control the actual transmission by the use of predetermined status signals. TCP/IP accomplishes all of this.

TCP and UDP

TCP is one of the most widely used transport layer protocols, expanding from its original implementation on the ARPANET to connecting commercial sites all over the world. On Day 1, "Open Systems, Standards, and Protocols," you looked at the OSI seven-layer model, which bears a striking resemblance to TCP/IP's layered model, so it is not surprising that many of the features of the OSI transport layer were based on TCP.

In theory, a transport layer protocol could be a very simple software routine, but TCP cannot be called simple. Why use a transport layer that is as complex as TCP? The most important reason depends on IP's unreliability. As you saw yesterday, IP does not guarantee delivery of a datagram; it is a connectionless system with no reliability. IP simply handles the routing of datagrams, and if problems occur, IP discards the packet without a second thought (generating an ICMP error message back to the sender in the process). The task of ascertaining the status of the datagrams sent over a network and handling the resending of information if parts have been discarded falls to TCP, which can be thought of as riding shotgun over IP.

Most users think of TCP and IP as a tightly knit pair, but TCP can be (and frequently is) used with other protocols without IP. For example, TCP or parts of it are used in the File Transfer Protocol (FTP) and the Simple Mail Transfer Protocol (SMTP), both of which do not use IP.

What Is TCP?

The Transmission Control Protocol provides a considerable number of services to the IP layer and the upper layers. Most importantly, it provides a connection-oriented protocol to the upper layers that enable an application to be sure that a datagram sent out over the network was received in its entirety. In this role, TCP acts as a message-validation protocol providing reliable communications. If a datagram is corrupted or lost, TCP usually handles the retransmission, rather than the applications in the higher layers.

TCP manages the flow of datagrams from the higher layers to the IP layer, as well as incoming datagrams from the IP layer up to the higher level protocols. TCP has to ensure that priorities and security are properly respected. TCP must be capable of handling the termination of an application above it that was expecting incoming datagrams, as well as failures in the lower layers. TCP also must maintain a state table of all data streams in and out of the TCP layer. The isolation of all these services in a separate layer enables applications to be designed without regard to flow control or message reliability. Without the TCP layer, each application would have to implement the services themselves, which is a waste of resources.

TCP resides in the transport layer, positioned above IP but below the upper layers and their applications, as shown in Figure 4.1. TCP resides only on devices that actually process datagrams, ensuring that the datagram has gone from the source to the target machine. It does not reside on a device that simply routes datagrams, so there is usually no TCP layer in a gateway. This makes sense, because on a gateway the datagram has no need to go higher in the layered model than the IP layer.

Because TCP is a connection-oriented protocol responsible for ensuring the transfer of a datagram from the source to destination machine (end-to-end communications), TCP must receive communications messages from the destination machine to acknowledge receipt of the datagram. The term virtual circuit is usually used to refer to the communications between the two end machines, most of which are simple acknowledgment messages (either confirmation of receipt or a failure code) and datagram sequence numbers.

Following a Message

To illustrate the role of TCP, it is instructive to follow a sample message between two machines. The processes are simplified at this stage, to be expanded on later today. The message originates from an application in an upper layer and is passed to TCP from the next higher layer in the architecture through some protocol (often referred to as an upper-layer protocol, or ULP, to indicate that it resides above TCP). The message is passed as a stream—a sequence of individual characters sent asynchronously. This is in contrast to most protocols, which use fixed blocks of data. This can pose some conversion problems with applications that handle only formally constructed blocks of data or insist on fixed-size messages.

TCP receives the stream of bytes and assembles them into TCP segments, or packets. In the process of assembling the segment, header information is attached at the front of the data. Each segment has a checksum calculated and embedded within the header, as well as a sequence number if there is more than one segment in the entire message. The length of the segment is usually determined by TCP or by a system value set by the system administrator. (The length of TCP segments has nothing to do with the IP datagram length, although there is sometimes a relationship between the two.)

If two-way communications are required (such as with Telnet or FTP), a connection (virtual circuit) between the sending and receiving machines is established prior to passing the segment to IP for routing. This process starts with the sending TCP software issuing a request for a TCP connection with the receiving machine. In the message is a unique number (called a socket number) that identifies the sending machine's connection. The receiving TCP software assigns its own unique socket number and sends it back to the original machine. The two unique numbers then define the connection between the two machines until the virtual circuit is terminated. (I look at sockets in a little more detail in a moment.)

After the virtual circuit is established, TCP sends the segment to the IP software, which then issues the message over the network as a datagram. IP can perform any of the changes to the segment that you saw in yesterday's material, such as fragmenting it and reassembling it at the destination machine. These steps are completely transparent to the TCP layers, however. After winding its way over the network, the receiving machine's IP passes the received segment up to the recipient machine's TCP layer, where it is processed and passed up to the applications above it using an upper-layer protocol.

If the message was more than one TCP segment long (not IP datagrams), the receiving TCP software reassembles the message using the sequence numbers contained in each segment's header. If a segment is missing or corrupt (which can be determined from the checksum), TCP returns a message with the faulty sequence number in the body. The originating TCP software can then resend the bad segment.

If only one segment is used for the entire message, after comparing the segment's checksum with a newly calculated value, the receiving TCP software can generate either a positive acknowledgment (ACK) or a request to resend the segment and route the request back to the sending layer.

The receiving machine's TCP implementation can perform a simple flow control to prevent buffer overload. It does this by sending a buffer size called a window value to the sending machine, following which the sender can send only enough bytes to fill the window. After that, the sender must wait for another window value to be received. This provides a handshaking protocol between the two machines, although it slows down the transmission time and slightly increases network traffic.

As with most connection-based protocols, timers are an important aspect of TCP. The use of a timer ensures that an undue wait is not involved while waiting for an ACK or an error message. If the timers expire, an incomplete transmission is assumed. Usually an expiring timer before the sending of an acknowledgment message causes a retransmission of the datagram from the originating machine.

Timers can cause some problems with TCP. The specifications for TCP provide for the acknowledgment of only the highest datagram number that has been received without error, but this cannot properly handle fragmentary reception. If a message is composed of several datagrams that arrive out of order, the specification states that TCP cannot acknowledge the reception of the message until all the datagrams have been received. So even if all but one datagram in the middle of the sequence have been successfully received, a timer might expire and cause all the datagrams to be resent. With large messages, this can cause an increase in network traffic.

If the receiving TCP software receives duplicate datagrams (as can occur with a retransmission after a timeout or due to a duplicate transmission from IP), the receiving version of TCP discards any duplicate datagrams, without bothering with an error message. After all, the sending system cares only that the message was received—not how many copies were received.

TCP does not have a negative acknowledgment (NAK) function; it relies on a timer to indicate lack of acknowledgment. If the timer has expired after sending the datagram without receiving an acknowledgment of receipt, the datagram is assumed to have been lost and is retransmitted. The sending TCP software keeps copies of all unacknowledged datagrams in a buffer until they have been properly acknowledged. When this happens, the retransmission timer is stopped, and the datagram is removed from the buffer.

TCP supports a push function from the upper-layer protocols. A push is used when an application wants to send data immediately and confirm that a message passed to TCP has been successfully transmitted. To do this, a push flag is set in the ULP connection, instructing TCP to forward any buffered information from the application to the destination as soon as possible (as opposed to holding it in the buffer until it is ready to transmit it).

Ports and Sockets

All upper-layer applications that use TCP (or UDP) have a port number that identifies the application. In theory, port numbers can be assigned on individual machines, or however the administrator desires, but some conventions have been adopted to enable better communications between TCP implementations. This enables the port number to identify the type of service that one TCP system is requesting from another. Port numbers can be changed, although this can cause difficulties. Most systems maintain a file of port numbers and their corresponding service.

Typically, port numbers above 255 are reserved for private use of the local machine, but numbers below 255 are used for frequently used processes. A list of frequently used port numbers is published by the Internet Assigned Numbers Authority and is available through an RFC or from many sites that offer Internet summary files for downloading. The commonly used port numbers on this list are shown in Table 4.1. The numbers 0 and 255 are reserved.

Table 4.1. Frequently used TCP port numbers.

Port Number	Process Name	Description
1	TCPMUX	TCP Port Service Multiplexer
5	RJE	Remote Job Entry
7	ECHO	Echo
9	DISCARD	Discard
11	USERS	Active Users
13	DAYTIME	Daytime
17	Quote	Quotation of the Day
19	CHARGEN	Character generator
20	FTP-DATA	File Transfer Protocol•Data
21	FTP	File Transfer Protocol•Control
23	TELNET	Telnet
25	SMTP	Simple Mail Transfer Protocol
27	NSW-FE	NSW User System Front End
29	MSG-ICP	MSG-ICP
31	MSG-AUTH	MSG Authentication
33	DSP	Display Support Protocol
35		Private Print Servers
37	TIME	Time
39	RLP	Resource Location Protocol
41	GRAPHICS	Graphics
42	NAMESERV	Host Name Server
43	NICNAME	Who Is
49	LOGIN	Login Host Protocol
53	DOMAIN	Domain Name Server
67	BOOTPS	Bootstrap Protocol Server
68	BOOTPC	Bootstrap Protocol Client
69	TFTP	Trivial File Transfer Protocol
79	FINGER	Finger
101	HOSTNAME	NIC Host Name Server
102	ISO-TSAP	ISO TSAP
103	X400	X.400
104	X400SND	X.400 SND
105	CSNET-NS	CSNET Mailbox Name Server
109	POP2	Post Office Protocol v2
110	POP3	Post Office Protocol v3
111	RPC	Sun RPC Portmap
137	NETBIOS-NS	NETBIOS Name Service
138	NETBIOS-DG	NETBIOS Datagram Service
139	NETBIOS-SS	NETBIOS Session Service
146	ISO-TP0	ISO TP0
147	ISO-IP	ISO IP
150	SQL-NET	SQL NET
153	SGMP	SGMP
156	SQLSRV	SQL Service
160	SGMP-TRAPS	SGMP TRAPS
161	SNMP	SNMP
162	SNMPTRAP	SNMPTRAP
163	CMIP-MANAGE	CMIP/TCP Manager
164	CMIP-AGENT	CMIP/TCP Agent
165	XNS-Courier	Xerox
179	BGP	Border Gateway Protocol

Each communication circuit into and out of the TCP layer is uniquely identified by a combination of two numbers, which together are called a socket. The socket is composed of the IP address of the machine and the port number used by the TCP software. Both the sending and receiving machines have sockets. Because the IP address is unique across the internetwork, and the port numbers are unique to the individual machine, the socket numbers are also unique across the entire internetwork. This enables a process to talk to another process across the network, based entirely on the socket number.

The last section examined the process of establishing a message. During the process, the sending TCP requests a connection with the receiving TCP, using the unique socket numbers. This process is shown in Figure 4.2. If the sending TCP wants to establish a Telnet session from its port number 350, the socket number would be composed of the source machine's IP address and the port number (350), and the message would have a destination port number of 23 (Telnet's port number). The receiving TCP has a source port of 23 (Telnet) and a destination port of 350 (the sending machine's port).

The sending and receiving machines maintain a port table, which lists all active port numbers. The two machines involved have reversed entries for each session between the two. This is called binding and is shown in Figure 4.3. The source and destination numbers are simply reversed for each connection in the port table. Of course, the IP addresses, and hence the socket numbers, are different.

If the sending machine is requesting more than one connection, the source port numbers are different, even though the destination port numbers might be the same. For example, if the sending machine were trying to establish three Telnet sessions simultaneously, the source machine port numbers might be 350, 351, and 352, and the destination port numbers would all be 23.

It is possible for more than one machine to share the same destination socket—a process called multiplexing. In Figure 4.4, three machines are establishing Telnet sessions with a destination. They all use destination port 23, which is port multiplexing. Because the datagrams emerging from the port have the full socket information (with unique IP addresses), there is no confusion as to which machine a datagram is destined for.

When multiple sockets are established, it is conceivable that more than one machine might send a connection request with the same source and destination ports. However, the IP addresses for the two machines are different, so the sockets are still uniquely identified despite identical source and destination port numbers.

TCP Communications with the Upper Layers

TCP must communicate with applications in the upper layer and a network system in the layer below. Several messages are defined for the upper-layer protocol to TCP communications, but there is no defined method for TCP to talk to lower layers (usually, but not necessarily, IP). TCP expects the layer beneath it to define the communication method. It is usually assumed that TCP and the transport layer communicate asynchronously.

The TCP to upper-layer protocol (ULP) communication method is well-defined, consisting of a set of service request primitives. The primitives involved in ULP to TCP communications are shown in Table 4.2.

Table 4.2. ULP-TCP service primitives.

Command	Parameters Expected
ULP to TCP Service Request Primitives
ABORT	Local connection name
ACTIVE-OPEN	Local port, remote socket
	Optional: ULP timeout, timeout action, precedence, security, options
ACTIVE-OPEN-WITH-DATA	Source port, destination socket, data, data length, push flag, urgent flag
	Optional: ULP timeout, timeout action, precedence, security
ALLOCATE	Local connection name, data length
CLOSE	Local connection name
FULL-PASSIVE-OPEN	Local port, destination socket
	Optional: ULP timeout, timeout action, precedence, security, options
RECEIVE	Local connection name, buffer address, byte count, push flag, urgent flag
SEND	Local connection name, buffer address, data length, push flag, urgent flag
	Optional: ULP timeout, timeout action
STATUS	Local connection name
UNSPECIFIED-PASSIVE-OPEN	Local port
	Optional: ULP timeout, timeout action, precedence, security, options
TCP to ULP Service Request Primitives
CLOSING	Local connection name
DELIVER	Local connection name, buffer address, data length, urgent flag
ERROR	Local connection name, error description
OPEN-FAILURE	Local connection name
OPEN-ID	Local connection name, remote socket, destination address
OPEN-SUCCESS	Local connection name
STATUS RESPONSE	Local connection name, source port, source address, remote socket, connection state, receive window, send window, amount waiting ACK, amount waiting receipt, urgent mode, precedence, security, timeout, timeout action
TERMINATE	Local connection name, description

Passive and Active Ports

TCP enables two methods to establish a connection: active and passive. An active connection establishment happens when TCP issues a request for the connection, based on an instruction from an upper-level protocol that provides the socket number. A passive approach takes place when the upper-level protocol instructs TCP to wait for the arrival of connection requests from a remote system (usually from an active open instruction). When TCP receives the request, it assigns a port number. This enables a connection to proceed rapidly, without waiting for the active process.

There are two passive open primitives. A specified passive open creates a connection when the precedence level and security level are acceptable. An unspecified passive open opens the port to any request. The latter is used by servers that are waiting for clients of an unknown type to connect to them.

TCP has strict rules about the use of passive and active connection processes. Usually a passive open is performed on one machine, while an active open is performed on the other, with specific information about the socket number, precedence (priority), and security levels.

Although most TCP connections are established by an active request to a passive port, it is possible to open a connection without a passive port waiting. In this case, the TCP that sends a request for a connection includes both the local socket number and the remote socket number. If the receiving TCP is configured to enable the request (based on the precedence and security settings, as well as application-based criteria), the connection can be opened. This process is looked at again in the section titled "TCP and Connections."

TCP Timers

TCP uses several timers to ensure that excessive delays are not encountered during communications. Several of these timers are elegant, handling problems that are not immediately obvious at first analysis. The timers used by TCP are examined in the following sections, which reveal their roles in ensuring that data is properly sent from one connection to another.

The Retransmission Timer

The retransmission timer manages retransmission timeouts (RTOs), which occur when a preset interval between the sending of a datagram and the returning acknowledgment is exceeded. The value of the timeout tends to vary, depending on the network type, to compensate for speed differences. If the timer expires, the datagram is retransmitted with an adjusted RTO, which is usually increased exponentially to a maximum preset limit. If the maximum limit is exceeded, connection failure is assumed, and error messages are passed back to the upper-layer application.

Values for the timeout are determined by measuring the average time that data takes to be transmitted to another machine and the acknowledgment received back, which is called the round-trip time, or RTT. From experiments, these RTTs are averaged by a formula that develops an expected value, called the smoothed round-trip time, or SRTT. This value is then increased to account for unforeseen delays.

The Quiet Timer

After a TCP connection is closed, it is possible for datagrams that are still making their way through the network to attempt to access the closed port. The quiet timer is intended to prevent the just-closed port from reopening again quickly and receiving these last datagrams.

The quiet timer is usually set to twice the maximum segment lifetime (the same value as the Time to Live field in an IP header), ensuring that all segments still heading for the port have been discarded. Typically, this can result in a port being unavailable for up to 30 seconds, prompting error messages when other applications attempt to access the port during this interval.

The Persistence Timer

The persistence timer handles a fairly rare occurrence. It is conceivable that a receive window might have a value of 0, causing the sending machine to pause transmission. The message to restart sending might be lost, causing an infinite delay. The persistence timer waits a preset time and then sends a one-byte segment at predetermined intervals to ensure that the receiving machine is still clogged.

The receiving machine resends the zero window-size message after receiving one of these status segments, if it is still backlogged. If the window is open, a message giving the new value is returned, and communications are resumed.

The Keep-Alive Timer and the Idle Timer

Both the keep-alive timer and the idle timer were added to the TCP specifications after their original definition. The keep-alive timer sends an empty packet at regular intervals to ensure that the connection to the other machine is still active. If no response has been received after sending the message by the time the idle timer has expired, the connection is assumed to be broken.

The keep-alive timer value is usually set by an application, with values ranging from 5 to 45 seconds. The idle timer is usually set to 360 seconds.

Transmission Control Blocks and Flow Control

TCP has to keep track of a lot of information about each connection. It does this through a Transmission Control Block (TCB), which contains information about the local and remote socket numbers, the send and receive buffers, security and priority values, and the current segment in the queue. The TCB also manages send and receive sequence numbers.

The TCB uses several variables to keep track of the send and receive status and to control the flow of information. These variables are shown in Table 4.3.

Table 4.3. TCP send and receive variables.

Variable Name	Description
Send Variables
SND.UNA	Send Unacknowledged
SND.NXT	Send Next
SND.WND	Send Window
SND.UP	Sequence number of last urgent set
SND.WL1	Sequence number for last window update
SND.WL2	Acknowledgment number for last window update
SND.PUSH	Sequence number of last pushed set
ISS	Initial send sequence number
Receive Variables
RCV.NXT	Sequence number of next received set
RCV.WND	Number of sets that can be received
RCV.UP	Sequence number of last urgent data
RCV.IRS	Initial receive sequence number

Using these variables, TCP controls the flow of information between two sockets. A sample connection session helps illustrate the use of the variables. It begins with Machine A wanting to send five blocks of data to Machine B. If the window limit is seven blocks, a maximum of seven blocks can be sent without acknowledgment. The SND.UNA variable on Machine A indicates how many blocks have been sent but are unacknowledged (5), and the SND.NXT variable has the value of the next block in the sequence (6). The value of the SND.WND variable is 2 (seven blocks possible, minus five sent), so only two more blocks could be sent without overloading the window. Machine B returns a message with the number of blocks received, and the window limit is adjusted accordingly.

The passage of messages back and forth can become quite complex as the sending machine forwards blocks unacknowledged up to the window limit, waiting for acknowledgment of earlier blocks that have been removed from the incoming cue, and then sending more blocks to fill the window again. The tracking of the blocks becomes a matter of bookkeeping, but with large window limits and traffic across internetworks that sometimes cause blocks to go astray, the process is, in many ways, remarkable.

TCP Protocol Data Units

As mentioned earlier, TCP must communicate with IP in the layer below (using an IP-defined method) and applications in the upper layer (using the TCP-ULP primitives). TCP also must communicate with other TCP implementations across networks. To do this, it uses Protocol Data Units (PDUs), which are called segments in TCP parlance.

The layout of the TCP PDU (commonly called the header) is shown in Figure 4.5.

The different fields are as follows:

• Source port: A 16-bit field that identifies the local TCP user (usually an upper-layer application program).
  


• Destination port: A 16-bit field that identifies the remote machine's TCP user.
  


• Sequence number: A number indicating the current block's position in the overall message. This number is also used between two TCP implementations to provide the initial send sequence (ISS) number.
  


• Acknowledgment number: A number that indicates the next sequence number expected. In a backhanded manner, this also shows the sequence number of the last data received; it shows the last sequence number received plus 1.
  


• Data offset: The number of 32-bit words that are in the TCP header. This field is used to identify the start of the data field.
  


• Reserved: A 6-bit field reserved for future use. The six bits must be set to 0.
  


• Urg flag: If on (a value of 1), indicates that the urgent pointer field is significant.
  


• Ack flag: If on, indicates that the Acknowledgment field is significant.
  


• Psh flag: If on, indicates that the push function is to be performed.
  


• Rst flag: If on, indicates that the connection is to be reset.
  


• Syn flag: If on, indicates that the sequence numbers are to be synchronized. This flag is used when a connection is being established.
  


• Fin flag: If on, indicates that the sender has no more data to send. This is the equivalent of an end-of-transmission marker.
  


• Window: A number indicating how many blocks of data the receiving machine can accept.
  


• Checksum: Calculated by taking the 16-bit one's complement of the one's complement sum of the 16-bit words in the header (including pseudo-header) and text together. (A rather lengthy process required to fit the checksum properly into the header.)
  


• Urgent pointer: Used if the urg flag was set; it indicates the portion of the data message that is urgent by specifying the offset from the sequence number in the header. No specific action is taken by TCP with respect to urgent data; the action is determined by the application.
  


• Options: Similar to the IP header option field, this is used for specifying TCP options. Each option consists of an option number (one byte), the number of bytes in the option, and the option values. Only three options are currently defined for TCP:
  
  0 End of option list
  
  1 No operation
  
  2 Maximum segment size
  


• Padding: Filled to ensure that the header is a 32-bit multiple.
  

Following the PDU or header is the data. The Options field has one useful function: to specify the maximum buffer size a receiving TCP implementation can accommodate. Because TCP uses variable-length data areas, it is possible for a sending machine to create a segment that is longer than the receiving software can handle.

The Checksum field calculates the checksum based on the entire segment size, including a 96-bit pseudoheader that is prefixed to the TCP header during the calculation. The pseudoheader contains the source address, destination address, protocol identifier, and segment length. These are the parameters that are passed to IP when a send instruction is passed, and also the ones read by IP when delivery is attempted.

TCP and Connections

TCP has many rules imposed on how it communicates. These rules and the processes that TCP follows to establish a connection, transfer data, and terminate a connection are usually presented in state diagrams. (Because TCP is a state-driven protocol, its actions depend on the state of a flag or similar construct.) Avoiding overly complex state diagrams is difficult, so flow diagrams can be used as a useful method for understanding TCP.

Establishing a Connection

A connection can be established between two machines only if a connection between the two sockets does not exist, both machines agree to the connection, and both machines have adequate TCP resources to service the connection. If any of these conditions are not met, the connection cannot be made. The acceptance of connections can be triggered by an application or a system administration routine.

When a connection is established, it is given certain properties that are valid until the connection is closed. Typically, these are a precedence value and a security value. These settings are agreed upon by the two applications when the connection is in the process of being established.

In most cases, a connection is expected by two applications, so they issue either active or passive open requests. Figure 4.6 shows a flow diagram for a TCP open. The process begins with Machine A's TCP receiving a request for a connection from its ULP, to which it sends an active open primitive to Machine B. (Refer back to Table 4.2 for the TCP primitives.) The segment that is constructed has the SYN flag set on (set to 1) and has a sequence number assigned. The diagram shows this with the notation "SYN SEQ 50," indicating that the SYN flag is on and the sequence number (Initial Send Sequence number or ISS) is 50. (Any number could have been chosen.)

The application on Machine B has issued a passive open instruction to its TCP. When the SYN SEQ 50 segment is received, Machine B's TCP sends an acknowledgment back to Machine A with the sequence number of 51. Machine B also sets an ISS number of its own. The diagram shows this message as "ACK 51; SYN 200," indicating that the message is an acknowledgment with sequence number 51, it has the SYN flag set, and it has an ISS of 200.

Upon receipt, Machine A sends back its own acknowledgment message with the sequence number set to 201. This is "ACK 201" in the diagram. Then, having opened and acknowledged the connection, Machine A and Machine B both send connection open messages through the ULP to the requesting applications.

It is not necessary for the remote machine to have a passive open instruction, as mentioned earlier. In this case, the sending machine provides both the sending and receiving socket numbers, as well as precedence, security, and timeout values. It is common for two applications to request an active open at the same time. This is resolved quite easily, although it does involve a little more network traffic.

Data Transfer

Transferring information is straightforward, as shown in Figure 4.7. For each block of data received by Machine A's TCP from the ULP, TCP encapsulates it and sends it to Machine B with an increasing sequence number. After Machine B receives the message, it acknowledges it with a segment acknowledgment that increments the next sequence number (and hence indicates that it has received everything up to that sequence number). Figure 4.7 shows the transfer of two segments of information—one each way.

The TCP data transport service actually embodies six subservices:

• Full duplex: Enables both ends of a connection to transmit at any time, even simultaneously.
  


• Timeliness: The use of timers ensures that data is transmitted within a reasonable amount of time.
  


• Ordered: Data sent from one application is received in the same order at the other end. This occurs despite the fact that the datagrams might be received out of order through IP, because TCP reassembles the message in the correct order before passing it up to the higher layers.
  


• Labeled: All connections have an agreed-upon precedence and security value.
  


• Controlled flow: TCP can regulate the flow of information through the use of buffers and window limits.
  


• Error correction: Checksums ensure that data is free of errors (within the checksum algorithm's limits).
  

Closing Connections

To close a connection, one of the TCPs receives a close primitive from the ULP and issues a message with the FIN flag set on. This is shown in Figure 4.8. In the figure, Machine A's TCP sends the request to close the connection to Machine B with the next sequence number. Machine B then sends back an acknowledgment of the request and its next sequence number. Following this, Machine B sends the close message through its ULP to the application and waits for the application to acknowledge the closure. This step is not strictly necessary; TCP can close the connection without the application's approval, but a well-behaved system would inform the application of the change in state.

After receiving approval to close the connection from the application (or after the request has timed out), Machine B's TCP sends a segment back to Machine A with the FIN flag set. Finally, Machine A acknowledges the closure, and the connection is terminated.

An abrupt termination of a connection can occur when one side shuts down the socket. This can be done without any notice to the other machine and without regard to any information in transit between the two. Aside from sudden shutdowns caused by malfunctions or power outages, abrupt termination can be initiated by a user, an application, or a system monitoring routine that judges the connection worthy of termination. The other end of the connection might not realize that an abrupt termination has occurred until it attempts to send a message and the timer expires.

To keep track of all the connections, TCP uses a connection table. Each existing connection has an entry in the table that shows information about the end-to-end connection. The layout of the TCP connection table is shown in Figure 4.9.

The meaning of each column is as follows:

• State: The state of the connection (closed, closing, listening, waiting, and so on).
  


• Local address: The IP address for the connection. When in a listening state, this is set to 0.0.0.0.
  


• Local port: The local port number.
  


• Remote address: The remote machine's IP address.
  


• Remote port: The port number of the remote connection.
  

User Datagram Protocol (UDP)

TCP is a connection-based protocol. There are times when a connectionless protocol is required, so UDP is used. UDP is used with both the Trivial File Transfer Protocol (TFTP) and the Remote Call Procedure (RCP). Connectionless communications don't provide reliability, meaning there is no indication to the sending device that a message has been received correctly. Connectionless protocols also do not offer error-recovery capabilities—which must be either ignored or provided in the higher or lower layers. UDP is much simpler than TCP. It interfaces with IP (or other protocols) without the bother of flow control or error-recovery mechanisms, acting simply as a sender and receiver of datagrams.

The UDP message header is much simpler than TCP's. It is shown in Figure 4.10. Padding can be added to the datagram to ensure that the message is a multiple of 16 bits.

The fields are as follows:

• Source port: An optional field with the port number. If a port number is not specified, the field is set to 0.
  


• Destination port: The port on the destination machine.
  


• Length: The length of the datagram, including header and data.
  


• Checksum: A 16-bit one's complement of the one's complement sum of the datagram, including a pseudoheader similar to that of TCP.
  

The UDP checksum field is optional, but if it isn't used, no checksum is applied to the data segment because IP's checksum applies only to the IP header. If the checksum is not used, the field should be set to 0.


For Further Information Visit This Site

Kemahiran Belajar

Belajar Cara Sistem PQRST

      Sistem PQRST adalah suatu cara yang diperkenalkan oleh EL Thomas dan Ha Rabinson dalam buku   mereka yang bertajuk "Improving Reading In Every Class". Berikut adalah lima item yang menjadi   tunjang sistem ini.

(a) Preview ( mengimbas Tajuk-tajuk Penting )Dalam item ini pelajar disarankan agar melihat tajuk utama dalam sesuatu bab dan   seterusnya melihat tajuk-tajuk kecil yang menjadi rangka dalam menggambarkan maklumat atau   isi penting dalam keseluruhan bab.

(b) Question ( Menyoal )Daripada rangka ini, bina soalan yang boleh membantu anda mencari isi penting. Dengan   cara ini anda boleh mengingati sesuatu dengan lebih jelas.

(c) Read ( Membaca )Membaca sesuatu tajuk akan menjadi lebih bermakna kerana setiap ayat menjawab soalan   anda sendiri dari rangka topik

(d) Self-Recitation ( Menyebut Satu Persatu )Apabila anda sudah membaca, anda perlu mencatat atau melakar sesuatu gambarajah   berkaitan dengan apa yang difahami. Kemudian baca isi penting itu semula tanpa melihat nota   yang telah anda catatkan.

(e) Test ( Ujian )Untuk memastikan anda sudah memahami dan mengingati fakta sebaiknya, anda perlu membuat penilaian kendiri. Dua cara boleh dilaksanakan iaitu melaksanakan ujian-ujian tahun   lepas tanpa melihat rujukan dan menggunakan teknik soal jawab dengan bantuan rakan.

Bahan ini diterjemah dari:Improving Reading In Every ClassDitulis oleh: El Thomas dan Ha Rabinson

Rahsia Kejayaan
Doa dan Niat
Aturkan Sasaran, Cita-cita dan Matlamat
Rancangan atau Pelan Tindakan
Taat, Yakin dan Cintai Ilmu
Usaha yang Berkekalan

Teknik Belajar Berkesan
Kebanyakan pelajar, yang gagal di dalam pelajaran mereka bukan  kerana malas ataupun lemah. Mereka sebenarnya menghadapi  kesukaran ataupun tidak mengetahui cara-cara mengulangkaji  pelajaran mereka.

Terdapat beberapa kaedah yang dapat membantu pelajar-pelajar sebagai panduan.
Menyediakan jadual pembelajaran secara sistematik.
Rutin belajar yang sama pada tiap-tiap hari bagi melatih otak menerima tabiat belajar.
Pilihlah masa untuk mengulangkaji sewaktu semangat belajar di tahap maksimum.
Elakkan perkara-perkara yang mengganggu proses pembelajaran. Ahli keluarga harus bertolak ansur dalam memberi ruang untuk anda belajar.
Nota yang telah dibuat hendaklah diulangkaji pada hari yang sama.
Anda akan mendapat lebih manfaat sekiranya anda mempunyai matlamat belajar.
Elakkan belajar di tempat yang boleh menyebabkan rasa mengantuk.
Belajarlah dengan tujuan menimba ilmu bukanlah sekadar untuk lulus peperiksaan.

Pelajar-pelajar yang kandas adalah pelajar-pelajar yang :
Tidak mempunyai jadual belajar yang tetap dan hanya bergantung kepada "mood" untuk belajar.

Tidak suka mengulangkaji pelajaran dan selalu mengulangkaji pelajaran di saat-saat akhir peperiksaan.
Mengganggap TV dan lagu dapat membantu memudahkan  mengulangkaji pelajaran.
Belajar semata-mata untuk peperiksaan.    

Bahan ini diterjemah dari :
-Learning Skill Center
The University of Texas a
t Austin(Study Tips)

Kelebihan Solat

Diriwayatkan daripada Hazrat Abu Hurairah RA katanya,

Saya telah mendengar Rasulullah SAW bersabda, “Jika sebatang anak sungai mengalir di hadapan pintu rumah salah seorang daripada kamu dan dia mandi dalam sungai itu sebanyak lima kali sehari, pada pendapat kamu masih adakah lagi kekotoran (pada badannya)?”

Para sahabat R.Anhum menjawab, “Tidak akan tertinggal sedikitpun kekotoran.” Rasulullah SAW bersabda, “Maka demikianlah juga solah lima waktu, melalui solah ALLAH TAALA akan mengampunkan dosa.”

(Hadith riwayat Imam Bukhari dan Muslim)

Diriwayatkan dari Hazrat Jabir RA katanya, Rasulullah SAW bersabda, “Perumpamaan solah lima waktu ialah seperti seseorang yang mandi di sebatang sungai yang dalam yang mengalir di hadapan rumahnya sebanyak lima kali sehari.”

ANIMASI ADA DI SINI

SIFAT WUDUK RASULULLAH

Menurut bahasa, kalimah wuduk apabila dibaca dengan (أَلْوُضُوْءُ) iaitu dengan didhammahkan huruf wawnya, ia bermaksud perbuatan berwuduk. Dan apabila difathahkan wawnya, maka (أَلْوَضُوْءُ) ia bermaksud air wuduk.

Wuduk menurut syara ialah: Menggunakan air bersih (suci lagi mensucikan) untuk membasuh anggota-anggota tertentu yang telah ditetapkan oleh syara.

Berwuduk untuk solat adalah merupakan perintah dari Allah Azza wa-Jalla sebagaimana firmanNya:

يَا اَيُّهَا الَّذِيْنَ آمَنُوْا اِذَا قُمْتُمْ اِلَى الصَّلاَةِ فَاغْسِلُوْا وُجُوْهَكمْ وَاَيْدِيَكُمْ اِلَى الْمَرَافِقِ وَامْسَحُوْا بِرُؤُوْسِكُمْ وَأَرْجُلَكُمْ اِلَى الْكَعْبَيْنِ.

“Wahai orang-orang yang beriman, apabila kamu akan mendirikan solat maka basuhlah muka kamu dan tangan-tangan kamu hingga siku-siku kamu dan sapulah kepala kamu serta (basuhlah) kaki-kaki kamu sehingga ke kedua mata kaki!”. Al-Maidah. 5:6.

Tidak sah solat seseorang tanpa bersuci atau berwuduk terlebih dahulu, sebagaimana perintah dan penjelasan dari hadis-hadis sahih:

لاَ صَلاَةَ لِمَنْ لاَ وُضُوْءَ لَهُ.

“Tidak ada solat bagi orang yang tidak berwuduk”. H/R Ahmad, Abu Daud dan Ibnu Majah.

لاَ يَقْبَلُ اللهُ صَلاَةً بِغَيْرِ الطُّهُوْرِ

“Allah tidak menerima solat tanpa bersuci (berwuduk)”. H/R Muslim 1/60.

لاَتُقْبَلُ صَلاَةُ اَحَدِكُمْ اِذَا اَحْدَثَ حَتَّى يَتَوَضَّأَ.

“Tidak diterima solat seseorang antara kamu jika berhadas sehinggalah dia berwuduk”. H/R Bukhari, 1/206. Muslim, No. 225.

مِفْتَاحُ الصَّلاَةِ الطُّهُوْرُ ، وَتَحْرِيْمُهَا التَّكْبِيْرُ ، وَتَحْلِيْلُهَا التَّسْلِيْمُ.

“Kunci solat itu ialah bersuci, diharamkan (melakukan sesuatu kecuali pekerjaan solat) setelah bertakbir dan penghalalannya ialah setelah memberi salam”. H/R Abu Daud. No 60. Tirmizi. No. 3. Dan Ibnu Majah. No 275

اِنَّمَا أُمِرْتُ بِالْوُضُوْءِ اِذَا قُمْتُ اِلَى الصَّلاَةِ

“Sesungguhnya aku diperintah agar berwuduk apabila aku ingin mendirikan solat”. H/R Abu Daud 3760. Tirmizi 1848. Nasaii 1/73. Disahihkan oleh Al-Albani. Lihat: as-Sahihah. 57621.

WUDUK YANG SEMPURNA MENGHAPUSKAN DOSA-DOSA

Pengambilan wuduk yang sempurna bukan sahaja menjamin diterimnya solat tetapi ianya juga dapat menghapuskan dosa-dosa selagi tidak melakukan kesyirikan. Rasulullah sallallahu ‘alaihi wa-sallam bersabda:

عَنْ اَبِيْ هُرَيْرَةَ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : اِذَا تَوَضَّأَ الْعَبْدُ الْمُسْلِمُ - أَوِ الْمُؤْمِنُ - فَغَسَلَ وَجْهَهُ ، خَرَجَ مِنْ وَجْهِهِ كُلُّ خَطِيْئَةٍ نَظَرَ اِلَيْهَا بِعَيْنِهِ مَعَ الْمَآءِ أَوْ مَعَ آخِرِ قَطْرِ الْمَآءِ فَاِذَا غَسَلَ يَدَيْهِ خَرَجَتْ مِنْ يَدَيْهِ كَلُّ خَطِيْئَةٍ كَانَ بَطَشَتْهَا يَدَاهُ مَعَ الْمَآءِ اَوْ مَعَ آخِرِ قَطْرِ الْمَآءِ ، فَاِذَا غَسَلَ رِجْلَيْهِ خَرَجَتْ كَلُّ خَطِيْئَةٍ مَشَتْهَا رِجْلاَهُ مَعَ الْمَآءِ اَوْ مَعَ آخِرِ قَطْرِ الْمَآءِ حَتَّى يَخْرُجَ نَقِيًّا مِنَ الذُّنُوْبِ.

“Dari Abu Hurairah radiallahu ‘anhu berkata: Telah bersabda Rasulullah sallallahu ‘alaihi wa-sallam: Apabila seseorang hamba muslim atau mukmin berwuduk maka setelah ia membasuh wajahnya, keluarlah dari wajahnya segala dosa yang telah dilihat oleh kedua matanya melalui air atau bersama titisan air yang terakhir. Ketika membasuh kedua tangannya keluarlah dari kedua tangannya setiap dosa yang telah dilakukan oleh kedua tangannya bersama air atau bersama titisan air yang terakhir. Sewaktu ia membasuh kedua belah kakinya, keluarlah dari kedua kakinya setiap dosa yang dilangkah oleh kedua kakinya bersama air atau bersama air terakhir sehinggalah setelah ia selesai berwuduk ia bersih dari dosa-dosanya”. H/R Muslim 1/148

وَعَنْ عُثْمَانَ رَضِيَ اللهُ عَنْهُ اَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ : مَنْ تَوَضَّأَ فَاَحْسَنَ الْوُضُوْءَ خَرَجَتْ خَطَايَاهُ مِنْ جَسَدِهِ حَتَّى تَخْرُجَ مِنْ تَحْتِ أَظْفَارِهِ.

“Dari Umar radiallahu ‘anhu berkata: Sesungguhnya Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Barangsiapa berwuduk dengan sebaik-baik wuduk maka akan keluar dosa-dosanya dari tubuhnya sehingga ia keluar dari celah-celah kukunya”. H/R Muslim 3/133.

مَنْ تَوَضَّأَ هَكَذَا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ وَكَانَتْ صَلاَتُهُ وَمَشْيُهُ اِلَى الْمَسْجِدِ نَافِلَةً.

“Barangsiapa yang berduduk seperti ini (seperti wuduknya Rasulullah), diampunkan dosa-dosanya yang telah berlalu dan solat serta perjalanannya ke masjid adalah dipenuhi pahala”. H/R Msulim 3/113

عَنْ أَبِيْ مَالِكِ اْلأَشْعَرِيْ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : اَلطُّهُوْرُ شَطْرُ اْلإيْمَانِ.

“Dari Abu Malik al-Asy’ari radiallahu ‘anhu berkata: Telah bersabda Rasulullah sallallahu ‘alaihi wa-sallam: Bersuci itu sebahagian dari iman”. H/R Muslim. 1/140

عَنْ حُمْرَانَ ابْنِ أَبَانَ ، أَنَّ عُثْمَانَ رَضِيَ اللهُ عَنْهُ دَعَا بِوُضُوْءٍ ، فَذَكَرَ صِفَةَ وُضُوْءِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ ، ثُمَّ قَالَ : مَنْ تَوَضَّأَ مِثْلَ وُضُوْئِيْ هَذَا ، ثُمَّ قَامَ فَصَلَّى رَكْعَتَيْنِ لاَ يُحَدِّثُ فِيْهِمَا نَفْسَهُ غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ.

“Dari Humran bin Aban, bahawasanya Uthman radiallahu ‘anhu meminta air untuk berwuduk, lalu dia menyebutkan sifat wuduk Nabi sallallahu ‘alaihi wa-sallam kemudian beliau berkata di penghujung hadis: Barangsiapa yang berwuduk seperti wudukku ini, kemudian ia mendirikan solat dua rakaat dengan tidak berkata-kata yang keji pada diriya maka (wuduk dan solatnya) maka diampunkan baginya segala dosa-dosa yang telah berlalu”. H/R Bukhari 11/213. Muslim 226. Dan An-Nasaii. 1/698

مَنْ تَوَضَّأَ فَأَحْسَنَ الْوُضُوْءَ ، ثُمَّ رَاحَ فَوَجَدَ النَّاسَ قَدْ صَلُّوْا ، أَعْطَاهُ اللهُ مِثْلَ اَجْرِمَنْ صَلاَهَا وَحَضَرَهَا لاَيَنْقُصُ ذَلِكَ مِنْ أَجْرِهِمْ شَيْئًا

“Barangsiapa berwuduk lalu menyempurnakan wuduknya kemudian ia pergi ke masjid, lalu ia dapati orang-orang sudah selesai mengerjakan solat maka Allah memberikan pahala kepadanya sebagaimana pahala orang yang sudah solat, tidak dikurangi sedikitpun dari ganjaran yang mereka perolehi”. H/R Abu Daud No. 564. Nasaii. No. 865. Disahihkan oleh Al-Albani. Lihat: Sahih Jamiu as-Saghir. No. 6039

عَنْ أَبِيْ هُرَيْرَةَ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : أَلاَ أَدُلُّكُمْ عَلَى مَا يَمْحُوْ اللهُ بِهِ الْخَطَايَا وَيَرْفَعُ بِهِ الدَّرَجَاتِ ؟ قَالُوْا : بَلَى يَا رَسُوْلَ اللهِ ، قَالَ : اِسْبَاغُ الْوُضُوْءِ عَلَى الْمَكَارِهِ ، وَكَثْرَةُ الْخُطَا اِلَى الْمَسَاجِدِ ، وَانْتِظَارُ الْصَّلاَةِ بَعْدَ الصَّلاَةِ ، فَذَلِكُمُ الرِّبَاطُ ،فَذَلِكُمُ الرِّبَاطُ ،فَذَلِكُمُ الرِّبَاطُ.

“Dari Abu Hurairah radiallahu ‘anhu berkata: Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Mahukah aku tunjukkan kepada kamu beberapa perkara yang dengannya Allah akan menghapuskan dosa-dosa dan mengangkat derajat kamu? Mereka menjawab: Mahu wahai Rasulullah! Baginda bersabda: Iaitu menyempurnakan wuduk walau dalam keadaan susah (Kalimah مكاره yang jamaknya مكره ialah keadaan susah/sulit untuk mengerjakan wuduk, seperti dalam keadaan sakit atau terlalu sejuk), sering berjalan ke masjid (solat jamaah) dan menunggu solat setelah selesai menunaikan solat. Yang demikian itu adalah ribat (jihad/perjuangan), yang demikian itu ribat, yang demikian itu ribat”. H/r Muslim. 133

عَنْ أَبِيْ هُرَيْرَةَ رَضِيَ اللهُ عَنْهُ أَنَّ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ أَتْى الْمَقْبَرَةَ فَقَالَ : اَلسَّلاَمُ عَلَيْكُمْ دَارَ قَوْمِ مُؤْمِنِيْنَ وَاِنَّا اِنْ شَآءَ اللهُ بِكُمْ عَنْ قَرِيْبٍ لاَحِقُوْنَ ، وَدِدْتُ لَوْ أَنَّا قَدْ رَأيْنَا اِخْوَانَنَا ، قَالُوْا : أَوَ لَسْنَا اِخْوَانَكَ يَارَسُوْلَ اللهِ ؟ قَالَ : أَنْتُمْ أَصْحَابِيْ وَاِخْوَانُنَا الَّذِيْنَ لَمْ يَأْتُوْا بَعْدُ ! قَالُوْا : كَيْفَ تَعْرِفُ مَنْ لَمْ يَأْتِ مِنْ أُمَّتِكَ يَارَسُوْلَ اللهِ ؟ قَالَ : أَرَأَيْتَ لَوْ أَنَّ رَجُلاً لَهُ خَيْلٌ غُرِّ مُحَجَّلَةً بَيْنَ ظَهْرَى خَيْلٍ دُهْمٍ بُهْمٍ أَلاَ يَعْرِفُ خَيْلَهُ ؟ قَالُوْا : بَلَى يَا رَسُوْلَ اللهِ ، قَالَ : فَاِنَّهُمْ يَأْتُوْنَ غُرًّا مَحَجَّلِيْنَ مِنَ الْوُضُوْءِ ، وَأَنَا فَرَطُهُمْ عَلَى الْحَوْضِ ، أَلاَ لَيُذَادَنَّ رِجَالٌ عَنْ حَوْضِيْ كَمَا يُذَادُ الْبَعِيْرُ الضَّالُ ، أُنَادِيْهِمْ أَلاَ هَلُّمَ ، فَيُقَالُ : اِنَّهُمْ قَدْ بَدَّلُوْا بَعْدَكَ ، فَأقُوْلُ سُحْقًا سُحْقًا.

“Dari Abu Hurairah radiallahu ‘anhu berkata: Bahawa Rasulullah sallallahu ‘alaihi wa-sallam ketika sampai ke perkuburan, baginda mengucapkan salam: (Kesejahteraan atas kamu wahai penghuni negeri kaum mukminin, insya-Allah tidak lami lagi kami akan menyusul kamu). Alangkah gembiranya hatiku ketika hendak melihat saudara-saudaraku! Para sahabat berkata: Bukankah kami saudara-saudara engkau wahai Rasulullah? Baginda bersabda: Kamu ini adalah para sahabatku, adapun saudara-saudaraku ialah orang-orang yang belum muncul. Mereka bertanya: Bagaimana engkau dapat mengenali keadaan umat yang belum muncul itu wahai Rasulullah? Baginda menjawab: Bagaimana pendapat kamu, dimisalkan ada seorang mempunyai seekor kuda berwarna putih yang berada di tengah-tengah kuda yang berwarna hitam pekat, tidakkah ia dapat mengenali kuda itu? Benar wahai Rasulullah, ujar mereka! Baginda bersabda: Demikianlah halnya mereka itu, mereka datang dalam keadaan putih cermerlang bertanda disebabkan dari wuduk, sedangkan aku menjadi perintis mereka menuju telaga. Ketahuilah, sesungguhnya ada beberapa orang yang didorong masuk telaga sebagaimana unta yang sesat yang diusir, aku menyeru mereka: Marilah ke sini, marilah ke sini, marilah ke sini!” (H/R Malik, Nasaii 1/93-94. Ibnu Majah No. 4306. Ibnu Khuzaimah No. 6. Ahmad 2/300, 408. Muslim. 1/150.Lihat Mukhtasar Sahih Muslim No. 129. Baihaqi 4/78. Dan Abu Daud. No. 3237.)

عَنْ أَبِيْ أُمَامَةَ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ اِذَا تَوَضَّأَ الرَّجُلُ الْمُسْلِمُ خَرَجَتْ خَطَايَاهُ مِنْ سَمْعِهِ وَبَصَرِهِ وَيَدِهِ وَرِجْلَيْهِ ، فَاِذَا قَعَدَ ، قَعَدَ مَغْفُوْرًا لَهُ.

“Dari Abi Umamah radiallahu ‘anhu berkata: Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Apabila seseorang muslim berwuduk maka akan keluar dosa-dosanya dari pendengarannya (telinganya), matanya, tangannya dan dari kedua kakinya. Apabila ia duduk menanti solat, ia duduk dalam keampunan (diampunkan) dosa-dosanya”. H/R Ahmad. 5/252. Dihasankan oleh Nasruddin al-Albani rahimahullah dalam Jamiu as-Saghir. No. 461

TATACARA (SIFAT WUDUK) RASULULLAH

Berniat

Amalan niat di dalam hati tanpa dilafazkan dengan lisan, kerana niat adalah tempatnya di hati dan kerja hati bukan di lisan.

Maksud niat ialah menyengajakan atau bersungguh-sungguh untuk mengerjakan sesuatu kerana menunaikan perintah Allah Azza wa-Jalla. Syeikhul Islam Ibnu Taimiyah rahimahullah berkata:

“Tempat niat itu di hati, bukan di lisan sebagaimana yang disepakati oleh para imam kaum Muslimin, sama ada pada ibadah, taharah, solat, zakat, puasa, haji, membebaskan hamba, jihad dan selainnya. Jika diucapkan dengan lisannya tetapi berlainan dengan kehendak hatinya maka yang diterima hanya yang diniatkan oleh hatinya bukan lafaznya. Sebaliknya jika diucapkan niat dengan lisannya sedangkan berlainan dengan niat yang di hatinya maka ia tidak diterima menurut kesepakatan Imam-Imam Muslimin”. Lihat: Majmu’ ar-Rasail al-Kubra. 1/234

Setiap amal ibadah dituntut agar dimulakan dengan niat sebagaimana sabda Rasullullah sallallahu ‘alaihi wa-sallam:

اِنَّمَا اْلأَعْمَالُ بِالنِّيَاتِ ، وَاِنَّمَا لِكُلِّ امْرِىءٍ مَا نَوَى

“Setiap amal itu dimulakan dengan niat, sesungguhnya bagi setiap insan mengikut apa yang diniatkan”. H/R Bukhari. 1/9. Muslim. 6/48

Membaca Basmalah (bismillah):

Rasulullah sallallahu alaihi wa-sallam telah memerintahkan agar membaca basmalah (bismillah) setiap kali hendaka berwuduk. Baginda bersabda:

لاَ وُضُوْءَ لِمَنْ لَمْ يَذْكُرِاسْمَ اللهِ عَلَيْهِ.

“Tiada wuduk bagi siapa yang tidak menyebut nama Allah di atas wuduknya”. H/R Ahmad. Abu Daud 101. At-Tirmizi 26. Ibnu Majah 399. Lihat: Irwaul Ghalil. Dan disahihkan oleh Al-Albani dalam al-Jami’ 7444.

Diketika kekurangan air, Rasululllah sallallahu ‘alaihi wa-sallam pernah meminta air untuk berwuduk maka setelah memperolehi air, baginda memasukkan tangannya ke dalam air tersebut. Baginda memerintahkan para sahabat agar membaca basmalah ketika hendak berwuduk:

كَانَ وَضَعَ يَدَهُ فِى الْمَآءِ وَيَقُوْلُ : تَوَضَّؤُوْا بِسْمِ اللهِ ، فَرَاَيْتُ الْمَآءَ يَخْرُجُ مِنْ بَيْنِ اَصَابِعِهِ حَتَّى تَوَضَّؤُوْا مِنْ عِنْدِ آخِرِهِمْ ، قَالَ ثَابِتُ : قَلْتُ لأَنَسٍ : كَمْ تَرَاهُمْ ؟ قَالَ : نَحْوًا مِنْ سَبْعِيْنَ.

“Semasa Rasulullah meletakkan tangannya di dalam air, baginda bersabda: Berwuduklah kamu sekalian dengan nama Allah. Maka aku melihat air keluar dari celah-celah jari-jemari baginda sehinggalah orang yang terakhir (dapat berwuduk). Thabit bertanya (kepada Anas): Berapa jumlah mereka? Sekitar tujuh puluh orang (jawab Anas) ”. H/R Bukhari. 1/236. Muslim. 8/411. Dan Nasaii. 78

Telah dijelaskan oleh Ibnu Qudamah rahimahullah, bahawa berdasarkan hadis-hadis di atas maka menurut Imam Ahmad rahimahullah membaca bismillah ketika hendak berwuduk, hendak mandi dan bertayamum adalah wajib hukumnya. Al-Hasan al-Basri dan Ishaq bin Rahawiyh serta ramai para imam-imam yang lain juga berpendapat seperti itu. Menurut Ibnu Qudamah:

“Apabila ditetapkan wajibnya (membaca basmalah), jika ditinggalkan dengan sengaja maka taharahnya tidak sah kerana meninggalkan yang wajib dalam taharah sama seperti meninggalkan niat. Adapun jika meninggalkan dengan tidak disengajakan (terlupa) maka taharahnya tetap sah”. Lihat: Al-Mughni. 1/84

Membasuh kedua telapak tangan:

Disunnahkan membasuh kedua tangan sebelum memasukkannya ke dalam air atau sebelum berkumur-kumur. Dan dituntut agar mendahulukan yang sebelah kanan. Rasulullah sallallahu ‘alaihi wa-sallam bersabda:

عَنْ عَائِشَةَ رَضِيَ اللهُ عَنْهَا قَالَتْ : كَانَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يُحِبُّ التَّيَامُّنُ فِيْ تَنَعُّلِهِ ، وَتَرَجُّلِهِ ، وَطُهُوْرِهِ ، وَفِيْ شَأْنِهِ كُلِّهِ.

Dari Aisyah radiallahu ‘anha, bahawa Nabi sallallahu ‘alaihi wa-sallam menyukai mendahulukan yang kanan apabila memakai sandalnya (kasut), berjalan, bersuci dan dalam segala urusan”. H/R Ahmad, Bukhari dan Muslim

عَنْ أبِيْ هُرَيْرَةَ رَضِيَ اللهُ عَنْهُ ، أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ : اِذَا لَبِسْتُمْ وَاِذَا تَوَضَّأْتُمْ فَابْدَأُوْا بِأَيَامِنِكُمْ.

“Dari Abu Hurairah radiallahu ‘anhu, bahawa Nabi sallallahu ‘alaihi wa-sallam bersabda: Apabila kamu berpakaian, apabila kamu berwuduk maka mulakanlah dari anggota-anggota kanan kamu”. H/R Ahmad dan Abu Daud

Sangat ditekankan membasuh tangan ketika baru bangun dari tidur malam atau tidur yang lama, sebagaimana sabda Rasulullah sallallahu ‘alaihi wa-sallam:

وَعَنْ أَبِيْ هُرَيْرَةَ أَنَّ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ : اِذَا اسْتَيْقَظَ اَحَدُكُمْ مِنْ نَوْمِهِ فَلاَ يَغْمِسْ يَدَهُ حَتَّى يَغْسِلَهَا ثَلاَثًا ، فَاِنَّهُ لاَ يَدْرِيْ أَيْنَ بَاتَتْ يَدَهُ.

“Dari Abu Hurairah, bahawa Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Apabila salah seorang antara kamu bangun dari tidurnya maka janganlah memasukkan tangan ke dalam air sebelum membasuhnya tiga kali kerana ia tidak tahu di mana tangannya (berada semasa tidur)”. H/R Jamaah. Dalam riwayat Bukhari tidak disebut tiga kali

وَفِى لَفْظِ التِّرْمِذِيْ وَابْنِ مَاجَهْ : اِذَا اسْتَيْقَظَ اَحَدُكُمْ مِنَ اللَّيْلِ.

“Pada lafaz Tirmizi dan Ibnu Majah: Apabila salah seorang antara kamu bangun dari (tidur) malam”.

اَنَّ عُثْمَانَ دَعَا بِوُضُوْءٍ فَغَسَلَ كَفَّيْهِ ثَلاَثَ مَرَّاتٍ ، ثُمَّ قَالَ : رَأَيْتُ رَسُوْلَ اللهِ تَوَضَّأَ نَحْو وُضُوْئِيْ هَذَا.

“Bahawasanya Uthman pernah meminta air untuk berwuduk maka dibasuhnya kedua telapak tangannya tiga kali. Kemudian beliau berkata: Aku telah melihat Rasulullah berwuduk seperti wudukku ini”. H/R Bukhari dan Muslim

مِنْ حَدِيْثِ عَبْدِ اللهِ بْنِ زَيْدٍ رَضِيَ اللهُ عَنْهُ ، سُئِلَ عَنْ وُضُوْءِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ ، فَاَكْفَأَ عَلَى يَدَيْهِ مِنَ التَّوْرِ فَغَسَلَ يَدَهُ ثَلاَثًا.

“Dari hadis Abdillah bin Zaid radiallahu ‘anhu, beliau telah ditanya tentang wuduknya Nabi sallallahu ‘alaihi wa-sallam maka beliau menuangkan air dengan tangannya, lalu membasuh tangannya tiga kali”. H/R Bukhari. 1/255. Dan Muslim. 3/121

عَنْ أَوْسِ بْنِ أَبِيْ أَوْسٍ عَنْ جَدِّهِ قَالَ : رَأَيْتُ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ تَوَضَّأَ فَاسْتَوْكَفَ ثَلاَثًا ، أَيْ غَسَلَ كَفَّيْهِ.

“Dari Aus bin Abi Aus dari datuknya berkata: Aku telah melihat Rasulullah sallallahu ‘alaihi wa-sallam berwuduk maka baginda membasuh telapak tangannya tiga kali iaitu membasuh kedua telapak tangannya”. H/R Ahmad 4/9. An-Nasaii. 1 /55 dengan isnadnya yang sahih

Membasuh sela-sela (celah-celah) jari-jemari sama ada tangan atau kaki adalah perbuatan sunnah yang telah ditinggalkan, ia sangat dituntut kerana telah diperintahkan oleh Rasulullah sallallahu ‘alaihi wa-sallam:

وَعَنِ ابْنِ عَبَّاسٍ أَنَّ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ : اِذَا تَوَضَّأْتَ فَحَلِّلْ أَصَابِعَ يَدَيْكَ وَرِجْلَيْكَ.

“Dari Ibnu Abbas, bahawa Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Apabila kamu berwuduk, maka sela-selalah (celah-celah) jari-jemari kedua tangan kamu dan kaki kamu”. H/R Ahmad. Ibnu Majah dan Tirmizi

عَنْ لَقِيْطِ بْنِ صَبِرَةَ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : اَسْبِغِ الْوُضُوْءَ وَخَلِّلْ بَيْنَ اْلأَصَابِعِ.

“Dari Laqit bin Sabirah radiallahu ‘anhu berkata: Telah bersabda Rasulullah sallallahu ‘alaihi wa-sallam: Sempurnakanlah wuduk dan basuhlah sela-sela (celah-celah) jari-jemari kamu”. H/R Abu Daud No. 142. Tirmizi No. 38. Nasaii No. 114. Ibnu Majah No. 497. Hakim 1/148. Dan disahihkan oleh Al-Albani rahimahullah dalam Sahih Jami’ as-Sagir No. 940.

Menurut Imam San’ani (Lihat: Subulus Salam 1/47) rahimahullah:

“Secara lahirnya, lafaz jari-jemari yang dimaksudkan adalah jari-jemari kedua tangan dan kedua kaki. Ianya telah dijelaskan melalui hadis Ibnu Abbas”.

Syarih rahimahullah berkata: Hadis ini menunjukkan dituntut atau diperintahkan agar menyela-yela jari-jari kedua tangan dan kedua kaki. Dan hadis-hadis ini antara satu dengan yang lain saling memperkuat sehingga menunjukkan hukumnya menjadi wajib. Lihat: Nailul Autar. 1/131

Ketika berwuduk, disunnahkan juga menggerak-gerakkan cincin untuk menghilangan daki atau kotoran:

عَنْ أَبِيْ رَافِعٍ أَنَّ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ كَانَ اِذَا تَوَضَّأَ حَرَّكَ خَاتَمَهُ.

“Dari Abi Rafi’ bahawa Rasulullah sallallahu ‘alaihi wa-sallam apabila berwuduk, baginda menggerak-gerakkan cincinnya”. H/R Ibnu Majah dan Daraqutni

Syarih berkata: Hadis ini menunjukkan diperintahkan menggerak-gerakkan cincin agar hilang kotoran-kotoran yang berada di bawahnya, begitu juga yang sama dengan cincin seperti gelang, perhiasan-perhiasan dan sebagainya. Lihat: Nailul Autar. 1/131

Berkumur-kumur, Istinsyaq Dan Istinsar

Berkumur-kumur (أَلْمَضْمَضَةُ) ialah: Memasukkan air ke dalam mulut sambil beristinsyak (menggandingkan atau dengan serentak memasukkan air ke dalam hidung). Syariah berkata: Bahawa dalam mulut dan hidung termasuk muka. (Lihat: Nailul Autar. 1/125) Ketika berkumur-kumur hendaklah menggerak-gerakkan air di dalam mulut dengan bersungguh-sungguh.

Menurut Imam An-Nawawi rahimahullah: “Dari hadis ini (hadis Amru bin Yahya), diambil dalil yang menunjukkan bahawa mazhab yang paling benar ialah sunnah diketika berkumur-kumur dengan membasuh (memasukkan air) ke hidung dengan melakukan kedua-duanya serentak pada setiap kali (berwuduk) dengan tiga kali cedukan air”. Lihat: Sahih Muslim. 3/123

وَعَنْ عَائِشَةَ رَضِيَ اللهُ عَنْهَا فِى وَصْفِ وُضُوْءِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ اَنَّهُ قَالَ فِيْهِ : اِذَا تَوَضَّاَ فَمَضْمَضَ.

“Dari Aisyah radiallahu ‘anha pada mensifati wuduk Nabi. Bahawa apabila baginda berwaduk, baginda berkumur-kumur”. H/r Bukhari dan Abu Daud. 143

Istinsyak (اَلاِسْتِنْشَاقُ) ialah: Memasukkan air ke dalam hidung dengan tangan kanan, menggerakkan air di dalam hidung, membasuh dan kemudian menghembuskan keluar air tersebut. Cara mengeluarkan air dari hidung “istinsyak (أَْلإسْتِنْشَاقُ)” ialah setelah mengeluarkan air dari mulut (setelah berkumur-kumur). Rasulullah sallallahu ‘alaihi wa-sallam bersabda:

فَمَضْمَضَ وَاسْتَنْشَقَ مِنْ كَفٍّ وَاحِدَةٍ فَفَعَلَ ذَلِكَ ثَلاَثًا.

“Baginda berkumur-kumur memasukkan air ke hidung (serentak) dengan sebelah tangan dan melakukannya tiga kali”. H/R Bukhari 1/255. Muslim. 3/121

Istinsar (اَلاِسْتِنْثَارُ) ialah: Bersungguh-sungguh menghirup atau memasukkan air ke hidung dengan tangan kanan (jika tidak berpuasa), kemudian menghembuskan (menyemburkan) air tersebut dari hidung dengan tangan kiri:

عَنْ لَقِيْطِ بْنِ صَبِرَةَ رَضِيَ اللهُ عَنْهُ قَالَ : يَا رَسُوْلَ اللهِ ، أَخْبِرْنِيْ عَنِ الْوُضُوْءِ ؟ قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : اَسْبِغِ الْوُضُوْءَ ، وَخَلِّل بَيْنَ اْلأَصَابِعِ ، وَبَالِغْ فِي اْلاِسْتِنْشَاقِ ، اِلاَّ اَنْ تَكُوْنَ صَائِمًا.

“Dari Laqit bin Sabirah radiallahu ‘anhu berkata: Wahai Rasulullah, khabarkan kepadaku tentang wuduk! Baginda bersabda: Sempurnakanlah wuduk kamu, sela-selalah celah-celah jari-jemari kamu dan basuhlah hidung dengan menyedut air ke hidung kecuali ketika kamu berpuasa”. H/R Tirmizi. 38. Abu Daud. 142. Ibnu Majah. 407. Ibnu Hibban, Hakim dan Az-Zahabi. Disahihkan oleh Ibnu Hajar

وَعَنْ عَلِيٍّ رَضِيَ اللهُ عَنْهُ اَنَّهُ دَعَا بِوُضُوْءٍ ، فَمَضْمَضَ وَاسْتَنْشَقَ وَنَثَرَ بِيَدِهِ الْيُسْرَى فَفَعَلَ هَذَا ثَلاَثًا ، ثُمَّ قَالَ : هَذَا طَهُوْرُ نَبِيَّ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ.

“Dari Ali radiallahu ‘anhu bahawa beliau meminta air wuduk, kemudian ia berkumur-kumur dengan menghisap air dengan hidungnya dan menyemburkan (menghembuskan) dengan tangan kirinya maka ia berbuat ini tiga kali, kemudian berkata: Inilah cara bersuci Nabi sallallahu ‘alaihi wa-sallam”. H/R Ahmad dan Nasaii

Hendaklah dipastikan iaitu ketika menghembuskan air dari hidung, ia dilakukan setelah berkumur-kumur (mengeluarkan air dari mulut) sebagaimana sabda Rasulullah sallallahu ‘alaihi wa-sallam:

اِذَا تَوَضَّأَ اَحَدُكُمْ فَلْيَجْعَلْ فِى اَنْفِهِ مَاءً ا ثُمَّ لْيَسْتَنْثِرْ

“Bersabda Rasululullah sallallahu ‘alaihi wa-sallam: Apabila seseorang kamu berwuduk maka hendaklah ia memasukkan air ke dalam hidungnya kemudian ia menyisihkan (menghembuskannya) keluar”. H/R Bukhari 1/229. Muslim. 237. Abu Daud 140

“Dari Abdi Khairin berkata: Suatu ketika kami sedang duduk memerhatikan Ali berwuduk maka beliau pun memasukkan air yang separuh takungan tangannya ke dalam mulutnya (serentak memasukkan ke dalam hidungnya). Beliau berkumur-kumur dan membasuh hidungnya. Setelah itu beliau menghembuskan keluar dengan tangan kirinya, beliau melakukannya demikian tiga kali. Kemudian beliau berkata: Barangsiapa yang suka untuk menyaksikan tatacara wuduk Rasulullah maka berwuduklah seperti ini”. H/R Ad-Darimy. Al-Albani mensahihkan hadis ini.

Membasuh Muka

Cara membasuh muka ialah bermula dari atas dahi (tempat tumbuhnya rambut) sehingga ke bawah dagu. Dari anak telinga kiri ke anak telinga kanan. Membasuh muka adalah perintah dari Allah Azza wa-Jalla. Allah berfirman:

فَاغْسِلُوْا وُجُوْهَكُمْ

“Dan basuhlah muka kamu”. Al-Maidah. 5:6

Di dalam hadis sahih, dari Humran bin Aban berkata bahawa cara Uthman bin Affan radiallahu ‘anhu berwuduk semasa mengajarkan sifat wuduk Nabi sallallahu ‘alaihi wa-sallam ialah:

“Beliau membasuh muka sebanyak tiga kali”. H/R Bukhari. 1/312. Muslim. 226

عَنِ الْمِقْدَامِ بْنِ مَعْدِيْ كَرِبَ رَضِيَ اللهُ عَنْهُ قَالَ : أُتِيَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ بِوُضُوْءٍ فَتَوَضَّأَ فَغَسَلَ كَفَّيْهِ ثَلاَثًا ، وَغَسَلَ وَجْهَهُ ثَلاَثًا.

“Dari Miqdam bin Ma’di Kariba radiallahu ‘anhu berkata: Telah diberi kepada Rasulullah sallallahu ‘alaihi wa-sallam air wuduk, lalu baginda berwuduk, kemudian ia membasuh kedua tapak tangannya tiga kali, kemudian membasuh mukanya tiga kali”. H/R Abu Daud

Batas muka yang wajib dibasuh ialah (sebagaimana dijelaskan di atas): Panjangnya dari sebelah atas dimulai dari bahagian yang ditumbuhi rambut (jambul) di kepala (di atas dahi), sehinggalah ke dagu dan janggut. Dan lebarnya bermula dari tepi telinga kanan sehinggalah ke bahagian tepi telinga kiri.

Sebahagian ulama seperti Abu Tsaur dan Ishak menghukum wajib mensela-sela janggut, jika meninggalkannya dengan sengaja maka wajib mengulangi wuduk dan solatnya kerana Nabi Muhammad sallallahu ‘alaihi wa-sallam sentiasa mensela-sela janggutnya dengan air semasa berwuduk:

عَنْ أَنَسٍ رَضِيَ اللهُ عَنْهُ : أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ كَانَ اِذَا تَوَضَّأَ أَخَذَ كَفًّا مِنْ مَآءٍ فَاَدْخَلَهُ تَحْتَ حَنَكِهِ فَخَلَّلَ بِهِ لِحْيَتَهُ وَقَالَ : هَكَذَا أَمَرَنِيْ رَبِّيْ عَزَّ وَجَلَّ.

“Dari Anas radiallahu ‘anhu, bahawa Nabi sallallahu ‘alaihi wa-sallam mengambil seceduk air lalu dimasukkan di bawah dagunya dan mensela-sela (menyilang-nyilang) air pada janggutnya. Kemudian baginda bersabda: Beginilah yang diperintahkan oleh Tuhanku Azza wa-Jalla”. H/R Abu Daud 145. Baihaqi. 1/54. Hakim. 1/49. Menurut al-Albani: Hadis sahih. Lihat: Al-Jamiu as-Saghir. 4572.

عَنْ عُثْمَانَ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ كَانَ يُخَلِّلُ لِحْيَتَهُ.

“Dari Uthman, bahawa sesungguhnya Nabi sallallahu ‘alaihi wa-sallam mensela-sela air pada janggut baginda”. H/R At-Tirmizi. 31. Disahihkan olehnya. Ibnu Majah. 430. Hakim 1/149. Ibnu Khuzaimah. Ibnu Hibban. Menurut Tirmizi, Hakim dan Ibnu Khuzaimah, hadis sahih. Lihat: Kitab Syarus as-Sunnah, 1/421. Al-Bagawi. Dan Tahzibut Tahzib. 5/69.

Membasuh Kedua Tangan Hingga Ke Siku

Siku (مرفق) ialah tempat percantuman antara hasta (lengan sebelah bawah) dengan lengan sebelah atas. (Lihat: Kamus Muhith) Allah Azza wa-Jalla berfirman:

وَاَيْدِيَكُمْ اِلَى الْمَرَافِقِ

“Dan (basuhlah) tangan-tanganmu sehingga ke siku-sikumu”. Al-Maidah. 5:6

عَنْ نُعَيْمِ بْنِ الْمُجْمِرِ قَالَ : رَأَيْتُ اَبَا هُرَيْرَةَ يَتَوَضَّأَ فَغَسَلَ وَجْهَهُ فَأَسْبَغَ الْوُضُوْءَ ، ثُمَّ غَسَلَ يَدَهُ الْيُمْنَى حَتَّى أَشْرَعَ فِى الْعَضُدِ ، وَفِى آخِرِ الْحَدِيْثِ قَالَ : هَكَذَا رَأَيْتُ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَتَوَضَّأَ.

“Dari Nu’aim bin al-Mujmir ia berkata: Aku pernah melihat Abu Hurairah berwuduk lalu ia menyempurnakan wuduknya, kemudian ia membasuh tangan kanannya hingga mengenai lengan atasnya (sikunya), kemudian membasuh tangan kirinya hingga mengenai bahagian lengan kirinya hingga mengenai bahagian lengan atasnya. Di akhir hadis ini Abu Hurairah berkata: Demikianlah aku melihat Rasulullah sallallahu ‘alaihi wa-sallam berwuduk”. H/R Muslim 1/246. Dalam Sahih Muslim 1/149

وَعَنْ جَابِرٍ رَضِيَ اللهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ اِذَا تَوَضَّأَ اَدَارَ الْمَاءَ عَلَى مِرْفَقَيْهِ.

“Dari Jabir radiallahu ‘anhu, bahawa Nabi sallallahu ‘alaihi wa-sallam berwuduk meratakan air hingga sampai kedua-dua sikunya”. H/R Daruqutni 1/15. Baihaqi 1/56. Disahihkan oleh Al-Albani dalam Al-Jamiu as- Saghir No. 4574

Menyapu (Mengusap) Air Ke Seluruh Kepala

Pendapat yang paling rajih cara menyapu air di kepala ialah menyapu sehingga ke seluruh bahagian kepala iaitu berdasarkan penjelasan Ibnu Qudamah (Lihat: Al-Mughni (Dalam persoalan wuduk)) rahimahullah bahawa:

“Terdapat sebahagian orang yang berpegang dengan pendapat bahawa: Menyapu kepala hanya sebahagian sudah memadai. Mereka berpendapat bahawa huruf (ب) dalam al-Quran (بِرُؤُوْسِكُمْ) bermakna sebahagian (التبعيض). Mereka menafsirkan ayat tersebut: Sapulah air pada sebahagian kepalamu. Walaubagaimanapun pendapat kami bahawa huruf (ب) bermakna: Seluruh kepala (الاِلصاق) sebagaimana firman Allah:

فَامْسَحُوْا بِرُؤُوْسِكُمْ

“Dan sapulah kepalamu (bermaksud: keseluruhan kepalamu)”.

Menurut Imam Asy-Syaukani rahimahullah:

“Sesungguhnya tidak ada penjelasan yang tepat yang boleh menafsirkan (ب) kepada erti sebahagian (التبعيض). Malah Sibaweih sendiri telah membantah tafsiran tersebut di 15 tempat di dalam kitab beliau”. Lihat: Nailul Autar 1/193

Keterangan dari hadis yang membuktikan bahawa Rasulullah sallallahu ‘alaihi wa-sallam menyapu (mengusap) seluruh kepala baginda ialah:

عَنْ عَبْدِ اللهِ بْنِ زَيْدٍ رَضِيَ اللهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَسَحَ رَأْسَهُ بِيَدَيْهِ ، فَأَقْبَلَ بِهِمَا وَأَدْبَرَ ، بَدَأَ بِمُقَدِّمِ رَأْسِهِ ، ثُمَّ ذَهَبَ بِهِمَا اِلَى قَفَاهُ ، ثُمَّ رَدَّهُمَا اِلَى الْمَكَانِ الَّذِيْ بَدَأَ مِنْهُ.

“Dari Abdullah bin Zaid radiallahu ‘anhu, bahawasanya Nabi sallallahu ‘alaihi wa-sallam menyapu (mengusap) kepala baginda dengan kedua tangannya maka ditemukan kedua tangannya, digerakkan ke belakang. Dimulakan dari bahagian hadapan kepalanya kemudian terus menyapu dengan kedua tangannya sehingga ke tengkuknya, kemudian dikembalikan semula kedua tangannya kebahagian dimana baginda bermula”. H/R Bukhari 1/251. Muslim 235. Tirmizi No. 28

Mengusap (Menyapu) Air Pada Kedua Telinga

Setelah menyapu air di kepala kemudian langsung mengusap kedua telinga di bahagian luar dan dalam telinga dengan sisa air di tangan. (Lihat: Sifat Wuduk Nabi. Hlm. 15. Abdullah bin Abdurrahman al-Jibrin) Menurut Syeikh al-Albani rahimahullah:

Tidak ada keterangan di dalam as-Sunnah yang mewajibkan pengambilan air baru untuk menyapu telinga. Maka memadailah dengan sisa air yang digunakan untuk menyapu kepala, sebagaimana hukumnya harus menyapu air di kepala dengan sisa air dari membasuh tangan. Yang demikian adalah berdasarkan kepada hadis Ar-Rabi’ binti Mu’awidz:

عَنِ الرَّبِيْعِ بِنْتِ مُعَوِّذٍ ، أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَسَحَ مِنْ فَضْلِ مَاءٍ كَانَ فِى يَدِهِ.

“Dari Rabi’ binti Mu’awiz bahawa nabi sallallahu ‘alaihi wa-sallam menyapu air di kepala baginda dengan sisa air yang ada pada kedua tangan baginda”. H/R Abu Daud. Lihat: Silsilah Dho’ifah. Hlm. 995

عَنِ ابْنِ عَبَّاسٍ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَسَحَ بِرَأْسِهِ وَأُذُنَيْهِ ظَاهِرَهُمَا وَبَاطِنَهُمَا.

“Dari Ibnu Abbas, bahawa nabi sallallahu ‘alaihi wa-sallam mengusap kepala dan kedua telinganya pada bahagian luar dan bahagian dalamnya”. H/R Ahmad 4/132. Abu Daud. 1/19 dengan sanad yang sahih. Disahihkan oleh al-Albani dalam Silsilah Ahadis Sahihah No. 261.

وَللنَّافِعِ : مَسَحَ بِرَأْسِهِ وَأُذُنَيْهِ ، بَاطِنِهِمَا بِالْمُسَبَّحَتَيْنِ.

“Dan bagi Nafi’: (Nabi) mengusap (menyapu) kepalanya dan kedua telinganya, bahagian dalamnya dengan kedua jari telunjuknya dan bahagian luarnya dengan ibu jarinya”. H/R Nasaii.

عَنْ عَبْدِ اللهِ بْنِ عَمْرُو رَضِيَ اللهُ عَنْهُ – في صِفَةِ الْوُضُوْءِ – قَالَ : ثُمَّ مَسَحَ بِرَأْسِهِ ، وَأَدْخَلَ أُصْبُعَيْهِ السَّبَّابَتَيْنِ فِى أُذُنَيْهِ ، وَمَسَحَ بِاِبْهَامَيْهِ ظَاهِرَ أُذُنَيْهِ.

“Dari Abdullah bin Amru radiallahu ‘anhu – pada mensifati wuduk Nabi – berkata: Kemudian baginda menyapukan air di kepala dan memasukkan kedua jari telunjuknya ke dalam telinga, lalu mengusap bahagian belakang kedua kuping telinga baginda dengan menggunakan kedua ibu jari baginda”. H/R Abu Daud 135. Nasaii 140. Ibnu Majah 422 dan disahihkan oleh Ibnu Khuzaimah.

Menurut Imam Ahmad rahimahullah, Ibnu Musayyib, ‘Ato, Al-Hasan al-Basri, Ibnu Sirin, Sa’ied bin Jubair, An-Nakhaie, At-Thauri dan Malik bahawa kedua telinga termasuk bahagian kepala maka hukum menyapunya sama dengan menyapu kepala. Kerana Rasulullah sallallahu ‘alahi wa-sallam bersabda:

وَلاِبْنِ مَاجَه مِنْ غَيْرِ وَجْهٍ : عَنِ النَّبِيِّ صَلَّىاللهُ عَلَيْهِ وَسَلَّمَ قَالَ : أَلأُذُنَانِ مِنَ الرَّأْسِ.

“Dari Ibnu Majah selain dari muka, dari Nabi salallahu ‘alaihi wa-sallam baginda bersabda: Kedua-dua telinga termasuk sebahagian dari kepala”. H/R Abu Daud. No. 134. Tirmizi No. 37. Ibnu Majah No. 44. Menurut al-Albani: Hadis sahih. Lihat: As-Silsilah As-Sahihah. 1/36.

Menyapu Serban Dan Ubun-Ubun (Jambul)

Bagi yang memakai serban (Perhatian: Serban tidak sama dengan songkok, kupiah atau topi kerana semua ini wajib ditanggalkan. Tidak boleh menyapu air di atas songkok, kupiah atau topi.), maka memadai menyapu di atas serbannya tanpa ditanggalkan atau menyapu di atas ubun-ubun kemudian di atas serbannya, sebagaimana amalan Nabi Muhammad sallallahu ‘alaihi wa-sallam:

عَنْ عَمْرِو بْنِ أُمَيَّةَ قَالَ : رَأيْتُ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَمْسَحُ عَلَى عِمَامَتِهِ وَخُفَّيْهِ.

“Dari ‘Amru bin Umaiyah berkata: Aku telah melihat Rasulullah sallallahi ‘alaihi wa-sallam menyapu air ke atas serban dan kedua sepatu baginda”. H/R Bukhari 1/266

Menurut Imam Ahmad rahimahullah, bahawa Nabi sallallahu ‘alaihi wa-sallam mengusap (menyapu dengan air) serban dan jambulnya, ini dilakukan sejalan (bersamaan) berdasarkan hadis Mughirah bin Syu’bah (Lihat: al-Mughni. 1/310) di bawah ini:

عَنِ الْمُغِيْرَةِ بْنِ شُعْبَةَ ، أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ تَوَضَّأَ فَمَسَحَ بَنَاصِيَتِهِ وَعَلَى الْعِمَامَةِ وَالْخُفَّيْنِ.

“Dari Mughirah bin Syubah, bahawa Nabi sallallahu ‘alaihi wa-sallam berwuduk lalu menyapu ubun-ubun (jambul) (Menurut Lisanu al-Arabi, kalimah (اَلنَّاصِيَةُ) ialah rambut yang tumbuh di dahi. Asal kalimahnya (اَلنُّصَّةُ) yang jamaknya (نُصَصٌ) bermakna jambul) dan atas serban serta dua sepatunya”. H/R Ahmad, Bukhari dan Muslim. 1/159.

عَنْ بِلاَلٍ رَضِيَ اللهُ عَنْهُ قَالَ : أنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَسَحَ الْخُفَّيْنِ وَالْخِمَارِ.

“Dari Bilal radiallahu ‘anhu berkata: Bahawa Nabi sallallahu ‘alaihi wa-sallam menyapu air di atas kedua sepatunya dan kain penutup kepalanya (serbannya)”. H/R Bukhari. No. 204-205. Muslim 1/159.

Menyapu Di Atas Telekong Atau Jilbab

Dibolehkan bagi para wanita mengusap (menyapu) air di atas telekong atau jilbabnya. Kenyataan ini berdasarkan amalan Ummah Salamah radiallahu ‘anha yang pernah mengusap (menyapu) air di atas jilbabnya. Hal ini telah di nyatakan oleh Ibnu Munzir. Lihat: Al-Mughni 1/312 dan 1/383-384.

Membasuh Dua Kaki

Diwajibkan membasuh dua kaki sampai kedua mata kaki atau buku lali. Allah Subhanahu wa-Ta’ala berfirman:

وَاَرْجُلَكُمْ اِلَى الْكَعْبَيْنِ

“Dan (basuhlah) kaki-kaki kamu sehingga kedua mata kaki”. Al-Maidah. 5:6.

عَنْ عُثْمَان بْنِ عَفَّان رَضِيَ اللهُ عَنْهُ اَنَّهُ دَعَا بِاِنَاءٍ ، فَأَفْرَغَ عَلَى كَفَّيْهِ ثَلاَثَ مَرَّاتٍ ، فَغَسَلَهُمَا ، ثُمَّ أَدْخَلَ يَمِيْنَهُ فِى اْلإِنَاءِ ، فَمَضْمَضَ وَاسْتَنْثَرَ ، ثُمَّ غَسَلَ وَجْهَهُ ثَلاَثًا ، وَيَدَيْهِ اِلَى الْمِرْفَقَيْنِ ثَلاَثَ مَرَّاتٍ ، ثُمَّ مَسَحَ بِرَأْسِهِ ، ثُمَّ غَسَلَ رِجْلَيْهِ ثَلاَثَ مَرَّاتٍ اِلَى الْكَعْبَيْنِ ، ثُمَّ قَالَ : رَأَيْتُ رَسُوْلَ اللهِ تَوَضَّأَ نَحْوَوُضُوْئِيْ هَذَا

“Dari Uthman bin Affan radiallahu ‘anhu, bahawa ia pernah meminta bejana, lalu ia menungkan air atas kedua telapak tangannya tiga kali, kemudian membasuhnya, lalu memasukkan yang sebelah kanannya dalam bejana, kemudian berkumur-kumur dan menghisap air ke hidung, kemudian membasuh mukannya tiga kali dan kedua tangannya sampai siku-siku tiga kali, kemudian mengusap kepalanya, lalu membasuh kedua kakinya tiga kali sampai mata kakinya, kemudian ia berkata: Aku melihat Rasulullah berwuduk seperti wudukku ini”. H/R Ahmad, Bukhari dan Muslim.

وَرَوَاهُ أَحْمَدُ وَقَالَ فِيْهِ : ثُمَّ يَمْسَحُ رَأْسَهُ كَمَا أَمَرَهُ اللهُ تَعَالَى ، ثُمَّ يَغْسِلُ قَدَمَيْهِ اِلَى الْكَعْبَيْنِ كَمَا أَمَرَهُ اللهُ.

“Dan diriwayatkan oleh Ahmad, ia berkata dalam hadis tersebut: Kemudian ia mengusap kepalanya sebagaimana yang diperintahkan oleh Allah kepadanya, kemudian ia memcuci kedua kakinya sehingga ke mata kaki sebagaimana yang diperintahkan oleh Allah kepadanya”.

عَنْ عَبْدِ اللهِ بْنِ عَمْرٍو قَالَ: تَخَلَّفَ عَنَّا رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ فِيْ سَفْرَةٍ ، فَأَدْرَكَنَا وَقَدْ أَرْهَقَنَا الْعَصْرُ ، فَجَعَلْنَا نَتَوَضَّأُ وَنَمْسَحُ عَلَى أَرْجُلِنَا ، قَالَ : فَنَادَى بَأَعْلَى صَوْتِهِ : وَيْلٌ للأَعْقَابِ مِنَ النَّارِ مَرَّتَيْنِ أَوْثَلاَثًا.

“Dari Abdillah bin Amr ia berkata: Rasulullah sallallahu ‘alaihi wa-sallam pernah tertinggal dari kami dalam satu perjalanan (safar), lalu ia menyusul kami, sedang waktu Asar telah meliwati kami, maka kami mulai berwuduk dan mengusap kaki-kaki kami. Abdullah bin Amr berkata: Kemudian Nabi sallallahu ‘alahihi wa-sallam memanggil dengan suara yang tinggi: Celaka bagi tumit-tumit dari nereka, dua kali atau tiga kali”. H/R Ahmad, Bukhari dan Muslim.

وَعَنْ أَبِيْ هُرَيْرَةَ رَضِيَ اللهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ رَأَى رَجُلاً لَمْ يَغْسِلْ عَقِبَهُ فَقَالَ : وَيْلٌ للأَعْقَابِ مِنَ النَّارِ.

Dan dari Abu Hurairah radiallahu ‘anhu, bahawa Nabi sallallahu ‘alaihi wa-sallam pernah melihat seorang lelaki yang membasuh tumitnya, lalu baginda bersabda: Celaka bagi tumit-tumit dari neraka”. H/R Muslim.

وَعَنْ جَابِرِ بْنِ عَبْدِ اللهِ قَالَ : رَأَى رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَوْمًا تَوَضَّأُوْا وَلَمْ يَمَسَّ أَعْقَابَهُمُ الْمَاءُ فَقَالَ : وَيْلٌ للأَعْقَابِ مِنَ النَّارِ.

“Dari Jabir bin Abdillah ia berkata: Rasulullah sallallahu ‘alaihi wa-sallam pernah melihat suatu kaum berwuduk sedang tumit-tumit mereka tidak terkena air, lalu ia bersabda: Celaka bagi tumit-tumit dari neraka”. H/R Ahmad.

وَعَنْ عَبْدِ اللهِ بْنِ الْحَارِثِ قَالَ : سَمِعْتُ رَسُوْلَ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَقُوْلُ : وَيْلٌ للأَعْقَابِ وَبُطُوْنِ اْلأَقْدَامِ مِنَ النَّارِ.

“Dari Abdullah bin al-Harith ia berkata: Aku pernah mendengar Rasulullah sallallahu ‘alaihi wa-sallam bersabda: Celaka bagi tumit-tumit dan dalam telapak-telapak kaki dari neraka”. H/R Ahmad dan Daruqutni.

وَعَنْ جَرِيْرِ بْنِ حَازِمٍ عَنْ قَتَادَةَ عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّ رَجُلاً جَاءَ اِلَى النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ وَقَدْ تَوَضَّأَ وَتَرَكَ عَلَى ظَهْرِ قَدَمِهِ مِثْلَ مَوْضِعِ الظُّفْرِ – فَقَالَ لَهُ النَّبِيُّ : اِرْجِعْ فَأَحْسِنْ وُضُوْءَ كَ.

“Dari Jarir bin Hazim dari Qtadah dari Anas bin Malik bahawa ada seorang lelaki yang datang kepada Nabi sedang ia telah berwuduk, ia meninggalkan punggung kakinya sebesar tempat kuku – lalu Nabi bersabda kepadanya: Ulangilah dan baguskanlah (sempurnakan) wadukmu”. H/R Abu Daud, Ahmad dan Durqutni.

Berkata Syariah: “Celaka bagi tumit-tumit dari neraka” bahawa hadis ini menunjukkan atas wajibnya membasuh dua kaki, begitulah pendapat jumhur. Lihat: Naulul Autar. 1/143.

Supaya lebih sempurna maka dibasuh kaki sampai ke betis sebagaimana yang ditunjukkan oleh Abu Hurairah radiallahu ‘anhu:

ثُمَّ غَسَلَ رِجْلَهُ الْيُمْنَى حَتَّى أَشْرَعَ فِى السَّاقِ ، ثُمَّ غَسَلَ رِجْلَهُ الْيُسْرَى حَتَّىأَشْرَعَ فِى السَّاقِ – وَفِىآخِرِالْحَدِيْثِ قَالَ : هَكَذَا رَأَيْتُ رَسُوْلَ اللهِ.

“Kemudian membasuh kaki kanannya sehingga ke paras betisnya kemudian membasuh kaki kirinya sehingga ke paras betisnya – Diakhir hadis beliau berkata: Beginilah aku lihat Rasulullah sallallahu ‘alaihi wa-sallam (berwuduk)”. H/R Muslim. 1/246.

Begitu juga supaya sentiasa sempurna hendaklah dibasuh celah-celah jari-jemari kaki dan mencela-cela dengan jari yang paling kecil iaitu mencela-cela menggunakan jari kelengkeng. Sebagaimana yang ditunjukkan oleh Rasulullah:

عَنِ الْمُسْتَوْرِدِ رَضِيَ اللهُ عَنْهُ قَالَ : كَانَ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ اِذَا تَوَضَّأَ دَلَّكَ أَصَابِعَ رِجْلَيْهِ بِخِنْصِرِهِ.

“Dari Al-Mustaurid radiallahu ‘anhu berkata: Bahawa Nabi sallallahu ‘alaihi wa-sallam apabila berwuduk menggosok-gosok (celah-celah) jari-jemari kedua kakinya dengan jari kelengkengnya”. H/R Abu Daud No. 148. Tirmizi no. 40. Ibnu Majah no. 446. Menurut Al-Albani: Hadis ini sahih. Lihat: Al-Jamiu as-Saghir. 4576.

Imam As-San’ani rahimahullah menjelaskan:

“Hadis ini adalah dalil yang menjelaskan kewajipan menggosok celah-celah jari-jemari, sebagaimana yang ditetapkan dari hadis Ibn Abbas, seperti yang telah kami jelaskan iaitu hadis yang telah diriwayatkan oleh Tirmizi, Ahmad, Ibnu Majah, al-Hakim dan dihukum hasan oleh Imam Bukhari. Adapun caranya ialah dengan menggosok-gosokkan dengan menggunakan jari kelengkeng tangan kiri bermula dengan bahagian bawah jari-jemari. Mengenai menggosok dengan tangan kiri maka sebenarnya ia tidak terdapat walaupun satu nas, hanya itulah yang dikatakan oleh Imam al-Ghazali, yang demikian diqiaskan kepada istinja. Lihat: Subus Salam Syarah Bulugul Maram. As-San’ani.

MEMBASUH SATU KALI, DUA KALI DAN TIGA KALI

Dibolehkan membasuh anggota wuduk satu kali satu kali, dua kali dua kali dan tiga kali tiga kali, tetapi tidak dibolehkan membasuh sehingga empat kali. Sepakat ulama bahawa membasuh sekali hukumnya wajib. Sementara membasuh dua kali dan tiga kali adalah sunnah. (Lihat Majmu al-Fatawa. 1/229.) Kecuali kepala dan telinga hanya diusap sekali (dan hukumnya bid’ah jika diusap melebeih sekali) usapan. (Lihat: Bidayatul Mujtahid 1/13. Tarjih Ibnu Rusyd.) Yang paling sempurna ialah mencontohi Nabi sallallahu ‘alaihi wa-sallam dengan melakukan tiga kali (selain kepala dan telinga). Adapun hadis-hadis yang membolehkan satu kali, dua kali dan tiga kali cucian ialah:

عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللهُ عَنْهُ قَالَ : تَوَضَّأَ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مَرَّةً مَرَّةً.

“Dari Ibnu Abbas radiallahu ‘anhu berkata: Telah berwuduk Nabi sallallahu ‘alaihi wa-sallam (dengan membasuh) satu kali, satu kali”. H/R Bukhari 1/226.

Ada kalanya Rasulullah sallallahu ‘aliaihi wa-sallam membasuh anggota wuduknya dua kali, dua kali.

عَنْ عَبْدِ اللهِ بْنِ زَيْدٍ رَضِيَ اللهُ عَنْهُ قَالَ : أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ تَوَضَّأَ مَرَّتَيْنِ مَرَّتَيْنِ.

“Dari Abdullah bin Zaid radiallahu ‘anhu berkata: Bahawa Nabi sallallahu ‘alaihi wa-sallam berwuduk (membasuh anggota wuduk) dengan dua kali, dua kali”. H/R Bukhari 1/226.

Ada kalanya baginda membasuh anggota wuduk dengan tiga kali, tiga kali:

كَانَ يَغْسِلُ اْلأَعْضَاءَ ثَلاَثَ مَرَّاتٍ.

“Baginda membasuh anggota-anggota wuduknya tiga kali”. H/R Bukhari dan Muslim.

وَعَنْ عُثْمَانَ أَنَّ النَّبِيَّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ تَوَضَّأَ ثَلاثًا ثَلاَثًا.

“Dari Uthman bahawa Nabi sallallahu ‘alaihi wa-sallam berwuduk (membasuh anggota wuduk) tiga kali tiga kali”. H/R Ahmad dan Muslim.

وَعَنْ عَمْرِو بْنِ شُعَيْبٍ رَضِيَ اللهُ عَنْهُ عَنْ أَبِيْهِ عَنْ جَدِّهِ قَالَ : جَآءَ أَعْرَابِيٌّ اِلَى رَسُوْلِ اللهِ صَلَّىاللهُ عَلَيْهِ وَسَلَّمَ يَسْأَلُهُ عَنِ الْوُضُوْءِ ، فَأرَاهُ ثَلاَثًا ثَلاَثًا وَقَالَ : هَذَا الْوُضُوْءُ فَمَنْ زَادَ عَلَى هَذَا فَقَدْ أَسَاءَ وَتَعَدَّى وَظَلَمَ.

“Dari Amr bin Syu’aib radiallahu ‘anhu dari ayahnya dari datuknya, ia berkata: Telah datang seorang Badwi kepada Rasulullah sallallahu ‘alaihi wa-sallam menanyakan masalah wuduk lalu Rasulullah sallallahu ‘alaihi wa-sallam memperlihatkannya tiga kali tiga kali dan baginda bersabda: Itulah bilangan wuduk maka barangsiapa menambah dari itu maka ia telah berbuat keburukan, pelanggaran dan kezaliman”. H/R Ahmad, Nasaii dan Ibnu Majah.

BERDOA SELEPAS BERWUDUK

Berkata Ibnu Qaiyim rahimahullah:

“Setiap hadis mengenai zikir ketika sedang berwuduk yang dibaca oleh orang awam bagi setiap anggota wuduk adalah bid’ah, tiada asalnya dari syara. Hadis-hadis mengenainya bercanggah dan dusta semata-mata. Nabi tidak pernah mengucapkannya dan tidak pernah mengajarkannya kepada ummah. Yang benar diterima dari Nabi hanyalah tasmiyah (membaca bismillah) pada permulaan wuduk dan selepas (selesai) berwuduk, tidak pula diriwayatkan sesuatu pun dari Nabi, tidak juga dari para sahabat, tabi’in bahkan tidak terdapat dari imam yang empat”.

Tiada sembarang apapun bacaan, doa atau zikir semasa berwuduk, sama ada sebelum atau semasa membasuh tangan, berkumur-kumur, membasuh muka atau semasa membasuh setiap anggota-anggota wuduk lainnya. Menurut Imam an-Nawawi rahimahullah:

“Semua doa-doa ketika sedang berwuduk tidak ada asalnya (dari syara), tidak pernah disebut oleh para salaf”.

Namun terdapat doa sejurus atau selepas berwuduk sebagaimana yang diamalkan oleh Rasulullah sallallahu ‘alaihi wa-sallam:

عَنْ عُمَرَ بْنِ الْخَطَّابِ رَضِيَ اللهُ عَنْهُ قَالَ : قَالَ رَسُوْلُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ : مَا مِنْكُمْ مِنْ أَحَدٍ يَتَوَضَّأُ فَيُسْبِغُ الْوُضُوْءَ ، ثُمَّ يَقُوْلُ :

“Dari Umar bin al-Khattab radiallahu ‘anhu berkata: Telah bersabda Rasulullah sallallahu ‘alaihi wa-sallam: Tiada seorang pun antara kamu yang berwuduk dengan sempurna, kemudian ia mengucapkan:

أَشْهَدُ اَنْ لاَ اِلَهَ اِلاَّ اللهُ وَحْدَهُ لاَشَرِيْكَ لَهُ ، وَاَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُوْلُهُ.

Pasti (yang membaca doa di atas ini) akan dibukakan baginya kelapan-lapan pintu syurga, ia boleh masuk yang mana dia kehendaki”. H/R Muslim No. 234. Abu Daud no. 169. Tirmizi No. 55. Nasaii. 148. Dan Ibnu Majah. 470.

Pada hadis riwayat Imam at-Tirmizi terdapat penambahan di hujungnya, iaitu:

اَللَّهُمَّ اجْعَلْنِيْ مِنَ التَّوَّابِيْنَ وَاجْعَلْنِيْ مِنَ الْمُتَطَهِّرِيْنَ.

“Ya Allah, jadikanlah aku golongan orang-orang yang bertaubat dan jadikanlah aku golongan orang-orang yang membersihkan diri!” Hadis ini disahihkan oleh Al-Albani rahimahullah.

“Dari Abi Sa’ied al-Khudri radiallahu ‘anhu berkata: Telah bersabda Nabi sallallahu ‘alaihi wa-sallam: Barangsiapa berwuduk kemudian setelah selesai ia membaca:

سُبْحَانَكَ اللَّهُمَّ وَبِحَمْدِكَ ، أَشْهَدُ أَنْ لاَ اِلَهَ اِلاَّ أَنْتَ أَسْتَغْفِرُكَ اَللَّهُمَّ وَأَتُوْبُ اِلَيْكَ.

Maka (dengan membaca doa ini) dituliskan di tempat tulisan, kemudian terpelihara dalam lambaran, maka tidak akan binasa sehingga ke hari kiamat”. Disahihkan oleh al-Albani. Lihat: Al-Jami’ 6046.

LIHAT ANIMASI