It is narrated from Sayyiduna Ali (may Allah be pleased with him) that Sayyiduna Ali (may Allah be pleased with him) prayed the Fajr prayer, then went to an open courtyard, and we went along with him. He called for water, and a boy brought a vessel containing water. Then Sayyiduna Ali (may Allah be pleased with him) took hold of the vessel with his right hand and poured water onto his left hand, then washed them both together; then he took hold of the vessel with his right hand and poured water onto his left hand, then washed them both together, and washed his palms three times before putting them into the vessel. At the end of it, it is stated that he (may Allah be pleased with him) said: "Whoever would like to see the ablution of the Messenger of Allah (peace and blessings be upon him), this is his (peace and blessings be upon him) ablution."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 213