The Messenger of Allah said: "Whoever stands (in he voluntary night prayer of) the Ramadan out of faith and in the hope of reward, his previous sins will be forgiven."
Sunan an-Nasa'i Book 47, Hadith 40
← Previous Hadith "Abdullah said: 'There are three (traits), whoever has them is a hypocrite: When he speaks, he lies; when he is entrusted with something, he betrays that trust; and when he makes a promise, he breaks it. Whoever has one of these (traits) then a trait of hypocrisy has not ceased in him, until he leaves it.'" (Sahih Mawquf)

Sunan an-Nasa'i Book 47, Hadith 39 Next Hadith → The Prophet said: "Whoever stands (in the voluntary night prayer of) Ramadan out of faith and in hope of reward, his previous sins will be forgiven."

Sunan an-Nasa'i Book 47, Hadith 41