If he happens to find water while he is already engaged in the prayer, the prayer is annulled; but once it has finished he is not required to repeat it.

The procedure is as follows: he forms the intention, pronounces the basmalah, then strikes clean earth with both hands—fingers spread—one time. The safer course is to strike twice¹, after removing any ring or the like. He then wipes his face with the inner sides of his fingers and his hands with the palms.

It is recommended² for anyone who expects to find water to delay tayammum until the end of the preferred time. With a single tayammum he may perform as many obligatory and supererogatory prayers as he wishes; however, if he undertakes tayammum specifically for a voluntary prayer, it does not render an obligatory prayer permissible.