Humran, the freed slave of 'Uthman, said
Uthman b. 'Affan called for ablution water and this is how he performed the ablution. He washed his hands thrice. He then rinsed his mouth and cleaned his nose with water (three times). He then washed his face three times, then washed his right arm up to the elbow three times, then washed his left arm like that, then wiped his head; then washed his right foot up to the ankle three times, then washed his left foot like that, and then said: I saw the Messenger of Allah (ﷺ) perform ablution like this ablution of mine. Then the Messenger of Allah (ﷺ) said: He who performs ablution like this ablution of mine and then stood up (for prayer) and offered two rak'ahs of prayer without allowing his thoughts to be distracted, all his previous sins are expiated. Ibn Shihab said: Our scholars remarked: This is the most complete of the ablutions performed for prayer.
Humran, the freed slave of 'Uthman said
I saw Uthman call for a vessel (of water) and poured water over his hands three times and then washed them. Then he put his right hand in the vessel and rinsed his mouth and cleaned his nose. Then he washed his face three times and his hands up to the elbow three times; then wiped his head, then washed his feet three times. Then he said that the Messenger of Allah (ﷺ) had said: He who performed ablution like this ablution of mine and offered two raka`ahs of prayer without allowing his thoughts to be distracted, all his previous sins would be expiated.