Hadithcore
Sahih Muslim, 231a
sahih

Humran b. Aban reported:

I used to fetch water for 'Uthman for his purification. Never was there a day that he did not take a bath with a small quantity of water. And Uthman said: The Messenger of Allah (ﷺ) at the time of our returning from our prayer told us (certain things pertaining to purification). Mis'ar said: I find that it was afternoon prayer. He said: I do not know whether I should tell you a thing or keep quiet. We said: Messenger of Allah, tell us if it is good and if it is otherwise, Allah and His Messenger know better. Upon this he said: A Muslim who purifies (himself) and completes purification as enjoined upon him by Allah and then offers the prayers, that will be expiation (of his sins he committed) between these (prayers).

حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ جَمِيعًا عَنْ وَكِيعٍ، قَالَ أَبُو كُرَيْبٍ حَدَّثَنَا وَكِيعٌ، عَنْ مِسْعَرٍ، عَنْ جَامِعِ بْنِ شَدَّادٍ أَبِي صَخْرَةَ، قَالَ سَمِعْتُ حُمْرَانَ بْنَ أَبَانَ، قَالَ كُنْتُ أَضَعُ لِعُثْمَانَ طَهُورَهُ فَمَا أَتَى عَلَيْهِ يَوْمٌ إِلاَّ وَهُوَ يُفِيضُ عَلَيْهِ نُطْفَةً ‏.‏ وَقَالَ عُثْمَانُ حَدَّثَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم عِنْدَ انْصِرَافِنَا مِنْ صَلاَتِنَا هَذِهِ - قَالَ مِسْعَرٌ أُرَاهَا الْعَصْرَ - فَقَالَ ‏"‏ مَا أَدْرِي أُحَدِّثُكُمْ بِشَىْءٍ أَوْ أَسْكُتُ ‏"‏ ‏.‏ فَقُلْنَا يَا رَسُولَ اللَّهِ إِنْ كَانَ خَيْرًا فَحَدِّثْنَا وَإِنْ كَانَ غَيْرَ ذَلِكَ فَاللَّهُ وَرَسُولُهُ أَعْلَمُ ‏.‏ قَالَ ‏"‏ مَا مِنْ مُسْلِمٍ يَتَطَهَّرُ فَيُتِمُّ الطُّهُورَ الَّذِي كَتَبَ اللَّهُ عَلَيْهِ فَيُصَلِّي هَذِهِ الصَّلَوَاتِ الْخَمْسَ إِلاَّ كَانَتْ كَفَّارَاتٍ لِمَا بَيْنَهَا ‏"‏ ‏.‏

References2 variants
In-Book Reference
Book 2, Hadith 13
USC-MSA web (English) reference
Book 2, Hadith 444 (deprecated numbering scheme)
Sharh · explanationclick to expand
Due to Allah’s grace, He makes performing acts of worship a reason for forgiveness. Thus, the Prophet ﷺ used to encourage people to perform them, by mentioning its reward. In this hadith, Humran ibn Aban, the servant of Othman ibn Affan, narrated that he used to fetch water of ablution for Othman. There was not a day that Othman did not take a bath with a small quantity of water. He was keen to purify himself, out of cleanliness and seeking great rewards mentioned in this hadith. Then, Othman narrated that one day the Prophet ﷺ finished the afternoon prayer and gave his companions the choice between speaking to them or keeping silent to draw their attention for knowledge. They replied, “If it is good, tell us about it, and if it is otherwise, Allah and His Prophet ﷺ know best.” Their response indicates their high good manners with the Prophet ﷺ. He told them that if a Muslim completely performs ablution and offers the five prayers at their appointed times - as in other narrations -, they will expiate what (sins) committed between them. In another narration in Sahih Muslim, he said, “Unless the major sins are committed.” Thus, the above-mentioned forgiveness is applied to the minor, not the major sins which Allah may forgive or punish its doer. Finally, this hadith contains the following benefits: (1) It shows the virtue of ablution, (2) It clarifies the virtue of regularly offering the acts of worship, which is a reason for forgiveness, and (3) It confirms the legitimacy of a ruler’s preaching to people, for Othman was then the caliph..