A healthy person who is in a state of major ritual impurity (janabah) and fears that the severe cold may prove fatal may resort to tayammum; the same concession applies to an ill person who fears his illness will worsen, his recovery will be delayed, or who has no one to bring him water. No one is obliged to purchase water for ablution when it is being sold at many times its normal price; only a slight surcharge that people customarily overlook is tolerated. A person who is junub and whose body is covered with numerous wounds performs tayammum and refrains from using water.

The same ruling applies to a person in minor impurity when the limbs required for wudu are heavily wounded. If, however, his wounds are few and he then enters the state of janabah, he must wash the sound parts of his body, wipe over the dressings and splints, and that suffices.

Tayammum is not valid without intention. Tayammum performed for janabah, for minor impurity, and for either obligatory or supererogatory prayers is governed by the same rules, except that when it is done because of janabah one must consciously recall that state and intend to remove it. Whoever lacks enough water is not required to combine partial wudu with tayammum.

The method of tayammum is to strike the palms once on clean earth, then wipe the face, covering it completely by passing the hands over it. He then strikes the earth a second time and wipes the right arm with the left hand and the left arm with the right up to the elbows. He begins with his right hand, running the inner side of the left fingers and palm over the back of the right hand and forearm to the elbow, then passes the inside of the left thumb over the back of the right thumb. He treats the left hand in the same way with the right. If, during tayammum, he gives precedence to the left hand over the right, the act is disliked but still valid, and the same ruling applies if he reverses the prescribed order.