From Sahih Muslim (Hadith 1782):
Abu Huraira reported Allah's Apostle (ﷺ) as saying:He who prayed on the Lailat-ul-Qadr (the Majestic Night) knowing that it is (the same night). I (believe) that he (the Prophet also) said: (He who does) it with faith and seeking reward (from Allah), his sins would be forgiven
Reference: Muslim 1782