The Book Of Faith and its Signs
47/21. Chapter:
Praying Qiyam in Ramadan
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ عَنْ مَالِكٍ عَنْ ابْنِ شِهَابٍ ح وَالْحَارِثُ بْنُ مِسْكِينٍ قِرَاءَةً عَلَيْهِ وَأَنَا أَسْمَعُ عَنْ ابْنِ الْقَاسِمِ قَالَ حَدَّثَنِي مَالِكٌ عَنْ ابْنِ شِهَابٍ عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ عَنْ أَبِي هُرَيْرَةَ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ مَنْ قَامَ رَمَضَانَ إِيمَانًا وَاحْتِسَابًا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ
It was narrated from Abu Hurairah that : The Prophet [SAW] said: "Whoever stands (in the voluntary night prayer of) Ramadan out of faith and in hope of reward, his previous sins will be forgiven."
Reference : Sunan an-Nasa'i 5025In-book reference : Book 47, Hadith 41English translation : Vol. 6, Book 47, Hadith 5028