Tayammum, in Islamic Law, can be defined as the use of pure earth to wipe over the hands and face with the intention of either removing oneself from a state of ritual impurity or of making prayer permissible.
Reasons for tayammum
Tayammum is permitted under the following two sets of circumstances:
The first of these is the absence of sufficient water for the performance of wudû’ or ghusl.
The second is the inability to use the available water on account of sickness or on account of severe cold whereby a person fears that using the water will bring about an illness, aggravate an existing illness, or delay recovery.
Conditions for tayammum
There are two conditions that apply exclusively to tayammum. The first condition applies to the performance of tayammum on account of the unavailability of water. It is that a person must seek out water until he has a preponderance of belief that water is unavailable.
The second condition applies to tayammum in general. It is that the earth used for it must be pure.
There are six other conditions as well, but these are shared by both tayammum and wudû’. They are Islam, sanity, discernment, termination of whatever breaks one’s state of purity, completion of any necessary cleaning of the private parts, and an intention.
Scholars differ as to whether an intention for purification is to be considered a condition of wudû’ and tayammum or one of the obligatory acts.
Obligatory acts of tayammum
There obligatory acts are four, two of which are agreed upon by all scholars. The two that are agreed upon are the wiping of the face and the wiping of the two hands up to the wrists with pure earth.
The two about which there is disagreement are to do so in a particular order (wiping the face first) and to complete the acts of tayammum in one continuous motion without pause.
Sunnah acts of tayammum
It is Sunnah to commence performing tayammum by invoking Allah’s name. Also, performing the acts of tayammum in order and without pause are recognized as Sunnah acts by those jurists who do not consider them to be obligatory.
Things that nullify tayammum
There are two factors that apply exclusively to the nullification of tayammum. The first of these applies to the performance of tayammum on account of the unavailability of water. In this case, a person’s tayammum will be nullified if sufficient water is found to perform the needed act of purification.
The second applies to the performance of tayammum on account of sickness or other preventative factors. In this case, a person’s tayammum will be nullified if the reason for abstaining from using the available water ceases to exist.
The following rulings apply to these nullifying factors:
If either of these two factors presents itself before the person who has made tayammum has begun to pray, then his tayammum will be nullified.
If a person prays after performing tayammum and neither of these two factors presents itself before the time for that prayer passes, then his tayammum will be considered valid.
These two rulings are a matter of juristic consensus (ijmâ`), as stated by Ibn Mundhir. [Kitâb al-Ijmâ` (34)]
Scholars differ concerning what happens if water becomes available or usable while a person who has made tayammum is busy with his prayer. They also disagree regarding what happens if water becomes available or usable after a person who has made tayammum has completed his prayer but before the time for the performance of that prayer has passed.
The other factors that nullify tayammum are the same as the factors that nullify a person’s wudû’ or ghusl. These include anything that comes out of the anus or the urinary tract, unconsciousness, and deep sleep.
This is a brief summary of the rulings of tayammum. Please note that the scholars of the various schools of Islamic Law have different ways of describing and presenting this information.