Harith reported,

Uthman sat down one day, and we sat with him. The caller to prayer came to him, so he called for water in a vessel, which I think held about a mudd, and he performed his ablution.Then he said, "I saw the Messenger of Allah ﷺ perform ablution as I have just done." Then he said, "Whoever performs ablution as I have done, then stands and prays the noon prayer, will be forgiven for whatever sins he committed between it and the morning prayer. Then when he prays the afternoon prayer, he is forgiven for what is between it and the noon prayer. Then when he prays the sunset prayer, he is forgiven for what is between it and the afternoon prayer. Then when he prays the night prayer, he is forgiven for what is between it and the sunset prayer. Then he may spend his night tossing about, but when he rises, performs ablution, and prays the morning prayer, he is forgiven for what is between it and the night prayer. These are the good deeds that wipe away the bad deeds."They asked, "These are the good deeds, but what are the lasting ones, Uthman?"He answered, "They are, There is no god but Allah, Glory be to Allah, Praise be to Allah, Allah is the Greatest, and There is no power and no strength except with Allah."

عن الحارث مولى عثمان بن عفان قال

جلس عثمان يوما، وجلسنا معه، فجاءه المؤذن، فدعا بماء في إناء، أظنه سيكون فيه مد، فتوضأ. ثم قال: رأيت رسول الله ﷺ يتوضأ وضوئي هذا، ثم قال: ومن توضأ وضوئي هذا، ثم قام فصلى صلاة الظهر، غفر له ما كان بينها وبين الصبح، ثم صلى العصر غفر له ما بينها وبين صلاة الظهر، ثم صلى المغرب غفر له ما بينها وبين صلاة العصر، ثم صلى العشاء غفر له ما بينها وبين صلاة المغرب، ثم لعله أن يبيت يتمرغ ليلته، ثم إن قام فتوضأ وصلى الصبح غفر له ما بينها وبين صلاة العشاء، وهن الحسنات يذهبن السيئات. قالوا: هذه الحسنات، فما الباقيات يا عثمان؟ قال: هن: لا إله إلا الله، وسبحان الله، والحمد لله، والله أكبر، ولا حول ولا قوة إلا بالله.