Musnad Ahmad 1173:1

Sufyan ibn ‘Uyaynah narrated to us, he said: ‘Abdullah ibn Muhammad ibn ‘Aqil ibn Abi Talib narrated to me, he said: ‘Ali ibn al-Husayn sent me to al-Rubayyi‘ bint Mu‘awwidh ibn ‘Afra’, so I asked her about the ablution (wudu) of the Messenger of Allah, peace and blessings of Allah be upon him. She brought out for him—meaning a vessel that was a mudd, or about a mudd and a quarter. Sufyan said: It is as if he refers to the Hashimi [vessel]. She said: "I used to bring out water for him in this, and he would pour it over his hands three times." And he said once: "He would wash his hands before inserting them [into the vessel], and he would wash his face three times, rinse his mouth three times, and inhale water into his nose three times." "And he would wash his right hand three times, and the left three times, and wipe his head." And he said once: "Twice, moving forward and backward, then he would wash his feet three times." [She said:] "A cousin of yours came to me and asked me—and he was Ibn ‘Abbas—so I informed him, and he said to me: 'I do not find in the Book of Allah except two wipings and two washings.'"