What are the conditions of the earth with which one can perform valid Tayammum (dry ablution) in terms of type and size? Is it permissible to use a stone that has been burned? Is it permissible to use a stone that is not exposed to the sun rays? Thank you.
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Maaliki and Hanafi scholars are of the view that it is permissible to perform Tayammum with a stone, provided that it is not changed to another substance through burning. If it is burned so that it is no longer customarily considered a stone, it is impermissible to use it for Tayammum. Al-Kharashi a Maaliki scholar, said: "It is permissible for both a sick as well as a healthy person who lacks water to perform Tayammum using a wall of mud bricks or stone, unless it is changed to lime or gypsum through burning or there is a barrier which prevents direct contact."
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