(39) باب ثَوَابِ مَنْ قَامَ رَمَضَانَ وَصَامَهُ إِيمَانًا وَاحْتِسَابًا وَالاِخْتِلاَفِ عَلَى الزُّهْرِيِّ فِي الْخَبَرِ فِي ذَلِكَ
It was narrated that Abu Hurairah said:
"The Messenger of Allah used to encourage (us) to pray Qiyam during Ramadan, without insisting on that, and he said: 'Whoever spends the nights of Ramadan in prayer (Qiyam) out of faith and in the hope of reward, he will be forgiven his previous sins'
Reference: Sunan an-Nasa'i 2198
In-book reference: Book 22, Hadith 109
English translation: Vol. 3, Book 22, Hadith 2200