And with this chain of narration, from al-Husayn ibn Sa'id, from Ibn Abi Umayr, from Ibn Udhaynah, from Muhammad ibn Muslim, who said: I asked Abu Abdullah عليه السلام about Tayammum (dry ablution). Imam عليه السلام struck the ground with his palms, then wiped his face with them. Then Imam عليه السلام struck the ground with his left hand and wiped with it from his elbow to the tips of his fingers - once over the back and once over the front. Then Imam عليه السلام struck the ground with his right hand and did with his left hand as he had done with his right. Imam عليه السلام then said: "This is Tayammum for what required Ghusl (ritual bath). As for Wudu' (ablution), it is for the face and the hands up to the elbows. The wiping of the head and feet is excluded in Tayammum, as they are not wiped with earth."