The Book of Fasting
22/39. Chapter:
The Reward of one who prays Qiyam in Ramadan and fasts the month out of faith and hope for reward
Sunan an-Nasai
أَخْبَرَنَا مُحَمَّدُ بْنُ خَالِدٍ، قَالَ حَدَّثَنَا بِشْرُ بْنُ شُعَيْبٍ، عَنْ أَبِيهِ، عَنِ الزُّهْرِيِّ، قَالَ حَدَّثَنَا أَبُو سَلَمَةَ بْنُ عَبْدِ الرَّحْمَنِ، أَنَّ أَبَا هُرَيْرَةَ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ لِرَمَضَانَ " مَنْ قَامَهُ إِيمَانًا وَاحْتِسَابًا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ " .
Abu Salamah bin 'Abdur-Rahman narrated that Abu Hurairah said: "I heard the Messenger of Allah say concerning Ramadan: 'Whoeve spends its nights in prayer (Qiyam) out of faith and in the hope of reward, he will be forgiven his previous sins." '
Reference : Sunan an-Nasa'i 2196In-book reference : Book 22, Hadith 107English translation : Vol. 3, Book 22, Hadith 2198