Is it valid to perform Tayammum (dry ablution with clean earth) by holding a stone as big as an egg and rubbing it over one’s hands and face?
All praise be to Allah Alone, and peace and blessings be upon His Messenger, and his family and Companions.
The basic ruling is that Tayammum should be done with pure earth whose dust particles cling to the hands, based on Allah’s Saying (which means):
...then perform Tayammum with clean earth and rub therewith your faces and hands.
(Part No. 5; Page No. 351) So, none of it when used can effectuate rubbing unless it has dust particles that cling to the hands.
Al-Shafi‘y related in his Musnad (Hadith compilation) on the authority of
`Aly, (may Allah be pleased with him) that the Messenger of Allah (peace be upon him) said:
“I was given what no other Prophet of Allah before me was given: dust is made for me a purifier ...”
Had materials other than dust been purifying, the Prophet (peace be upon him) would have mentioned it among the bounties that Allah (Exalted be He) granted him. However, if someone is in a place where there is no dust; it will suffice them to make Tayammum with available sand and the like. As for the stone mentioned in the question, using it will not be sufficient for Tayammum.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.