Narrated Abu Hurairah (RA): The Prophet (peace be upon him) said, "Whoever established prayers on the night of Qadr out of sincere faith and hoping for a reward from Allah, then all his previous sins will be forgiven; and whoever fasts in the month of Ramadan out of sincere faith, and hoping for a reward from Allah, then all his previous sins will be forgiven."
(Sahih al-Bukhari 1901, Book 30, Hadith 11)
(Sahih al-Bukhari 1901, Book 30, Hadith 11)