Chapter on Tayammum
A person in minor ritual impurity, as well as one in major ritual impurity (junub), may perform tayammum for several reasons, the first of which is the absence of water. If a traveller is certain that no water is available, he may perform tayammum without any search; but if he only suspects that water might be near, he must look for it among his own belongings and those of his companions, and survey the surrounding area if the terrain is level. Should this require moving about, he need only walk as far as his line of sight extends. If after that he finds nothing, he performs tayammum.
If he simply stays where he is, the sounder opinion is that he must nonetheless keep searching, for water may appear later. Should the traveller know of a water source that he can reach in time for his need, he is obliged to go to it provided he does not fear harm to life or property; if it lies beyond that distance, he may perform tayammum. If he becomes certain that water will be accessible at the very end of the prayer time, waiting for it is preferable; but if he merely deems it probable, then, according to the more apparent view, it is preferable to hasten tayammum.
When the water he finds is insufficient for a complete purification, the dominant position is that he must use whatever he has first and then perform tayammum. He is required to purchase water at its normal price unless he needs that amount to settle a debt that consumes his assets, to meet the essential costs of his journey, or to provide for an animal whose life is inviolable. If someone gifts him water or lends him a bucket, he must—on the sounder view—accept it; he is not, however, obliged to accept a gift of money with which to buy water.
If he forgets water in his luggage or misplaces it there and, after searching, fails to find it, he performs tayammum, yet—according to the more apparent view—he must afterward repeat the prayer. By contrast, if he mislays his luggage among other people’s baggage, he is not required to make up the prayer.