Musnad Ahmad

Abdu Khair (may Allah have mercy on him) says that once I was present in the service of Sayyiduna Ali (may Allah be pleased with him) when he had already performed the prayer. He asked for water. We began to wonder, after having prayed, what would he do with the water now? His purpose was only to teach us. So, a basin and a vessel were brought to him. He picked up the vessel and poured water over his hands and washed them three times. Then he poured it into the basin, rinsed his mouth three times, put water into his nose, cleaned his nose three times, and washed his face three times. He washed both his arms up to and including the elbows three times each. Then he put his hands back into the vessel and wiped his head once with both palms, and washed both his feet up to and including the ankles three times each. Then he said: Whoever wants to know the way of ablution of the Prophet (peace and blessings be upon him), the Prophet (peace and blessings be upon him) used to perform ablution in this manner.