The Book of Prayers (Kitab Al-Salat)

Muslim :: Book 4 : Hadith 1662

Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: He who observed prayer at night during Ramadan, because of faith and seeking his reward from Allah, his previous sins would be forgiven.

Source materials are from the University of Southern California MSA site
Hadith eBooks converted from Imaan Star