The companions stipulated that the soil must be lawfully available for use. If it is not lawfully available, tayammum with it is invalid, as when it has been stolen.

This issue is disputed (1), and the disagreement concerning it is like the disagreement over whether lawfully available water is a condition for wudu and ghusl.

However, if the soil is from land that has been wrongfully seized, tayammum with it is valid, just as if someone wrongfully seized a well, wudu with its water would be valid. Nevertheless, the jurists, may Allah have mercy on them, said: It is disliked to perform wudu with the water of a well located on wrongfully seized land.

Its obligatory acts are: wiping the face and the hands up to the wrists, ..............

His statement, “Its obligatory acts are: wiping the face and the hands up to the wrists”: The evidence for this is Allah’s saying, the Exalted: “Then wipe your faces and hands with it” [Quran 5:6]. This is like His saying concerning wudu: “O you who believe, when you rise for prayer, wash your faces and your hands up to the elbows” [Quran 5:6].

The wrist is the bone adjacent to the thumb. They composed the following verses:

The bone beside the thumb is the wrist; what lies
Beside the little finger is the karso'; the wrist-joint lies between.
And the bone beside the big toe is called the bu';
So hold fast to knowledge, and beware of error. (2)

The evidence that the wiping extends to the wrists is: