I saw ‘ Uthman b. ‘ Affan (perform ablution). He washed his forearms three times and washed his head thrice. He then said : I saw the Messenger of Allah (ﷺ) doing like that.

Abu Dawud said: Another version says: "He performed ablution three times only."
Sunan Abi Dawud Book 1, Hadith 110
← Previous Hadith I saw the Messenger of Allah (ﷺ) performing ablution as you saw me perform ablution. He then reported the tradition like that of al-Zuhrl and completed it.

Sunan Abi Dawud Book 1, Hadith 109 Next Hadith → Abdu Khayr said: Ali came upon us and he had already offered prayer. He called for water. We asked: What will you do with water when you have already offered prayer? - Perhaps to teach us. A utensil containing water and a wash-basin were brought (to him).

He poured water from the utensil on his right hand and washed both his hands three times, rinsed the mouth, snuffed up water and cleansed the nose three times. He then rinsed the mouth and snuffed up water with the same hand by which he took water. He then washed his face three times, and washed his right hand three times and washed his left hand three times. He then put his hand in water and wiped his head once.

He then washed his right foot thrice and left foot thrice, then said: If one is pleased to know the method of performing ablution of the Messenger of Allah, this is how he did it.

Sunan Abi Dawud Book 1, Hadith 111