Narrated 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).