I say, and with God's success: It is permissible to perform tayammum (dry ablution) on clay according to the correct opinion; because clay is of the same kind as the earth, and if the surface struck for tayammum is of the same kind as the earth, then it is permissible to perform tayammum with it without dust; because what is considered in tayammum is the touching, as it is required to place the hand on the earth, not to use a part of it, unless it has been overpowered by water, in which case tayammum with it is not permissible; due to His saying: {So perform tayammum from pure earth} (An-Nisa: 43). Al-said is a term for what appears on the surface of the earth of its kind: such as dust, sand, and stone. And from Hudhayfah, he said: The Prophet (peace be upon him) said: "We have been preferred over people in three things: Our rows have been made like the rows of angels, the whole earth has been made a mosque for us, and its soil has been made pure for us when we do not find water," in Sahih Muslim 1: 371, and Sahih Ibn Hibban 4: 595. See: Fath Bab al-‘Inayah 1: 116, and God knows best.