It is likewise permissible to perform tayammum with whatever lies upon the earth—whether ordinary soil, sabkha (salt-rich ground), sand, or anything similar. This is the sounder of the two scholarly positions, for Allah says, “then perform tayammum with clean earth” (Q 4:43). The Prophet ﷺ and his Companions, whenever the time for prayer overtook them, would perform tayammum with the very ground on which they intended to pray, be it soil or something else; they never carried special soil with them.

How to perform tayammum:
He strikes the soil once with both hands, fingers spread, then wipes his face with the inner sides of his fingers and wipes his hands with his palms, making sure the face and the hands are completely covered. If he prefers two strikes—using the first to wipe his face and the second to wipe the rest of his body—that is permissible, yet the first method is the one reported from the Prophet ﷺ.

Tayammum performed in place of minor ablution is nullified by anything that breaks wudu, and tayammum performed in place of a full ritual bath is nullified by whatever obligates ghusl, such as sexual defilement, menstruation, or post-partum bleeding, for a substitute shares the ruling of what it replaces. Tayammum is also nullified by the availability of water when it had been absent, and by the disappearance of the excuse—for example, recovery from illness—for which tayammum was legislated.

Whoever has neither water nor earth, or reaches a state in which he cannot bring water or earth into contact with his skin, must pray according to his circumstances—with no wudu and no tayammum—because Allah does not burden a soul beyond its capacity. He does not repeat that prayer, for he has done what he was commanded, as Allah says, “So fear Allah as much as you are able” (Q 64:16), and as the Messenger of Allah ﷺ said: