Musnad Ahmad 5:425

Yahya ibn Sa'id narrated to us, from Shu'bah, Malik ibn 'Urfutah narrated to me, I heard 'Abd Khayr say: I was with 'Ali, and a chair and a basin were brought to him. He said: "So he washed his palms three times, his face three times, and his forearms three times, and he wiped his head." Yahya described: "He began with the front of his head to its back, and I do not know if he returned his hand or not." And he washed his feet, then he said: "Whoever likes to look at the ablution of the Messenger of Allah, may Allah bless him and grant him peace, then this is the ablution of the Messenger of Allah, may Allah bless him and grant him peace." Abu 'Abd al-Rahman said to us: "Shu'bah erred in this; it is only from Khalid ibn 'Alqamah, from 'Abd Khayr."