Sahih Muslim, Chapter: Purification (Kitab Al-Taharah)

It was said to him (by people): Perform for us the ablution (as it was performed) by the Messenger of Allah (way peace be upon him). He ('Abdullah b. Zaid) called for a vessel (of water), and poured water from it on his hands and washed them three times. Then he inserted his hand (in the vessel) and brought it (water) out, rinsed his mouth and snuffed up water from the palm of one hand doing that three times, He again inserted his hand and brought it out and washed his face three times, then inserted his hand and brought it out and washed each arm up to the elbow twice, then inserted his hand and brought it out and wiped his head both front and back with his hands. He then washed his feet up to the ankles, and then said: This is how God's Messenger (peace be upon him) performed ablution.