Musnad Ahmad 5:810

'Abdullah narrated to us, my father Sufyan ibn Waki' ibn al-Jarrah narrated to me, from his father, from Abu Ishaq, from Abu Hayyah al-Wadi'i, from 'Amr Dhu Murr, who said: We saw 'Ali, may Allah be pleased with him, perform ablution. He washed his hands, rinsed his mouth, and sniffed water into his nose—he said: "And I am in doubt regarding the rinsing of the mouth and the sniffing of water, whether he mentioned them as three times or not"—and he washed his face three times, and his hands three times, each one of them three times, and he wiped his head and his ears—one of them said: "Then he took a handful of water and wiped his head with it." Then he stood up and drank the remainder of his ablution water. Then he said: "This is how the Prophet, may Allah bless him and grant him peace, used to perform ablution."