Hadith 1602

It was narrated from Abu Hurairah that: The Messenger of Allah (SAW) said: "Whoever prays Qiyam during Ramadan out of faith and in the hope of reward, he will be forgiven his previous sins."

أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مَنْ قَامَ رَمَضَانَ إِيمَانًا وَاحْتِسَابًا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ ‏"‏ ‏.‏

Reference: 1116100
In-book reference: Book 20, Hadith 1602
Hadith 1602 - The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day - Sunan an-Nasa'i - Sunnah.com