Sahih Ibn Khuzaymah

It is narrated from Humran, the freed slave of Sayyiduna Uthman (may Allah be pleased with him), that once Sayyiduna Uthman bin Affan (may Allah be pleased with him) called for water and performed ablution. He washed his hands three times, rinsed his nose (by putting water in it and blowing it out), then washed his face three times, then washed his right hand up to and including the elbow three times, then washed his left hand three times, then wiped his head, then washed his right foot up to and including the ankle three times, then likewise washed his left foot three times. Then he said, "I saw the Messenger of Allah (peace and blessings be upon him) perform ablution like this ablution of mine." Then the Messenger of Allah (peace and blessings be upon him) said: "Whoever performs ablution like this of mine, then stands and offers two rak‘ahs (voluntary prayer) in which he does not converse with himself, his past sins are forgiven." Ibn Shihab says that our learned scholars used to say, "This is the complete ablution which a person performs for prayer."