Tayammum is also an act of worship consisting of wiping the forehead and the two hands. It is a substitute for wudu\’ and ghusl. The Qur\’an says: O you who believe! … If you are sick, or on a journey, or one of you has come from toilet, or you have `touched\’ (i.e., had intercourse with) your women and you cannot find water, then you should do Tayammum on the pure earth by wiping a part of your face and your hands.