Musnad Ahmad 329:2

He said: I read to Abd al-Rahman ibn Mahdi, from Malik ibn Anas, from Amr ibn Yahya al-Mazini, from his father, that his grandfather said to Abdullah ibn Zayd ibn Asim, who was one of the companions of the Messenger of Allah, may Allah bless him and grant him peace: "Are you able to show me how the Messenger of Allah, may Allah bless him and grant him peace, used to perform ablution?" Abdullah ibn Zayd said: "Yes." He called for water for ablution, and he poured it onto his hands and washed his hands twice. Then he rinsed his mouth and cleared his nose three times. Then he washed his face three times. Then he washed his hands twice up to the elbows. Then he wiped his head with his hands, moving them forward and backward; he began at the front of his head, then took them to the back of his neck, then returned them to the place from which he began. Then he washed his feet.