Humran reported when 'Uthman performed ablution he said: By Allah, I am narrating to you a hadith had there not been this verse in the Book of Allah. I would not have narrated it to you. Verily I heard the Messenger of Allah (ﷺ) say: Not a person is there who performed ablution, and did it well, then offered prayer, but his sins (which he committed) were not pardoned between the prayer that he offered and the next one. 'Urwa said: The verse is this:" Those who suppress the clear proofs and the guidance which We have sent down"... to His words:" the Cursers" (ii. 15).
Source: sunnah.com
Other translations
Arabic
وَحَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا أَبِي، عَنْ صَالِحٍ، قَالَ ابْنُ شِهَابٍ وَلَكِنْ عُرْوَةُ يُحَدِّثُ عَنْ حُمْرَانَ، أَنَّهُ قَالَ فَلَمَّا تَوَضَّأَ عُثْمَانُ قَالَ وَاللَّهِ لأُحَدِّثَنَّكُمْ حَدِيثًا وَاللَّهِ لَوْلاَ آيَةٌ فِي كِتَابِ اللَّهِ مَا حَدَّثْتُكُمُوهُ إِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " لاَ يَتَوَضَّأُ رَجُلٌ فَيُحْسِنُ وُضُوءَهُ ثُمَّ يُصَلِّي الصَّلاَةَ إِلاَّ غُفِرَ لَهُ مَا بَيْنَهُ وَبَيْنَ الصَّلاَةِ الَّتِي تَلِيهَا " . قَالَ عُرْوَةُ الآيَةُ { إِنَّ الَّذِينَ يَكْتُمُونَ مَا أَنْزَلْنَا مِنَ الْبَيِّنَاتِ وَالْهُدَى} إِلَى قَوْلِهِ { اللاَّعِنُونَ}
sunnah.com