Sahih al-Bukhari 6433
صحيح البخاري#6433SahihNarrated Ibn `Abbas:I brought water to `Uthman bin `Affan to perform the ablution while he was sitting on his seat. He performed the ablution in a perfect way and said, "I saw the Prophet (ﷺ) performing the ablution in this place and he performed it in a perfect way and said, "Whoever performs the ablution as I have done this time and then proceeds to the mosque and offers a two-rak`at prayer and then sits there (waiting for the compulsory congregational prayers), then all his past sins will be forgiven." The Prophet (ﷺ) further added, "Do not be conceited (thinking that your sins will be forgiven because of your prayer)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 81:22