Hadith: Whoever performs ablution like this, his previous sins will be forgiven

عن عثمان بن عفان رضي الله عنه قال: رأيت رسول الله صلى الله عليه وسلم توضأ مِثل وُضوئي هذا، ثم قال: «مَنْ تَوَضَّأ هكَذَا، غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ، وَكَانَتْ صَلاَتُهُ وَمَشْيُهُ إِلَى المَسْجدِ نَافِلَةً».
[صحيح] - [رواه مسلم]

‘Uthmān ibn ‘Affān (may Allah be pleased with him) reported: I saw the Messenger of Allah (may Allah's peace and blessings be upon him) performing ablution the way I have just done it and then he said: "Whoever performs ablution like this, his previous sins will be forgiven and his prayer and walking to the mosque will be considered as supererogatory acts of worship."
Sahih/Authentic. - [Muslim]

Explanation

This Hadīth shows that ‘Uthmān ibn ‘Affān (may Allah be pleased with him) was performing ablution perfectly. He mentioned that he saw the Messenger of Allah (may Allah's peace and blessings be upon him) performing ablution in the same way as he did. He said that the Prophet (may Allah's peace and blessings be upon him) explained that if anyone performed ablution in that manner, Allah, the Exalted, will forgive all his previous minor sins that violated His rights and that his prayer and walking to the mosque will be rewarded with extra rewards in addition to the forgiveness of his sins. Himrān, the servant of ‘Uthmān, described the way that ‘Uthmān performed ablution. He said that ‘Uthmān called for a water vessel. He poured water into his palms and washed his hands three times. Then he put his right hand into the vessel and rinsed his mouth and nose. He then washed his face three times, his arms up to his elbows three time, wiped over his head, and finally washed his feet three times.