It is narrated from Abd Khayr al-Khaywani that a chair was brought for Sayyiduna Ali (may Allah be pleased with him), and he (may Allah be pleased with him) sat on it. Then a vessel of water was brought, and he washed his hands three times, then with a single (handful of) water rinsed his mouth and sniffed water into his nose three times, then washed his face three times with one hand, washed his arms three times, and placed his hand in the vessel, then wiped his head, moving his hands over his head from front to back, and it is not known whether he brought his hands back from back to front or not; and he washed his feet three times. Then he said: "Whoever would like to look at the ablution of the Prophet (peace and blessings be upon him), this is the ablution of the Prophet (peace and blessings be upon him)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 233