I was, with Uthman that he called for ablution water and said: I heard Allah's Messenger (ﷺ) say: When the time for a prescribed prayer comees, if any Muslim perform ablution well and offers his prayer) with humility and bowing, it will be an expiation for his past sins, so long as he has not committed a major sin; and this applies to for all times.

I brought for Uthman b. 'Affan the ablution water. He performed ablution and then said: Verily the people narrate from the Messenger of Allah (ﷺ) a hadith. I do not know what these are. but (I know this fact) that I saw the Messenger of Allah (ﷺ) perform ablution like this ablution of mine and then he said: He who performed ablution like this, all his previous sins would be expiated and his prayer and going towards the mosque would have an extra reward. In the tradition narrated by Ibn 'Abda (the words are): I came to Uthman and he performed ablution.

Should I not show you the ablution performed by Allah's Messenger (ﷺ)? And he then washed (the different parts of the body) three times. 4 Qutaiba has added in his narration the words: There were with him (with Uthman) Companions of Allah's Messenger (ﷺ).