Abdur Rahman bin Muhammad al-Maharbi عبد الرحمن بن محمد بن زياد المحاربي · The Book on Fasting

the Messenger of Allah said: "Whoever fasts Ramadan and stands (in the night prayer) for it out of faith and seeking a reward (from Allah), he will be forgiven what preceded of his sins. Whoever stands (in the night prayer) on the Night of Al-Qadr out of faith and seeking a reward (from Allah), he will be forgiven what preceded of his sins."