Volume 3, Book 32, Number 231:
Narrated Abu Huraira:
The Prophet said, “Whoever fasted the month of Ramadan out of sincere Faith (i.e. belief) and hop –
ing for a reward from Allah, then all his past sins will be forgiven, and whoever stood for the prayers
in the night of Qadr out of sincere Faith and hoping for a reward from Allah, then all his previous
sins will be forgiven .”