Sunan Ibn Majah, Chapter: The Book of the Sunnah

"The Messenger of Allah (saw) recited this Verse: 'For those who have done good is the best reward and even more.'[10:26] Then he said: 'When the people of Paradise enter Paradise, and the people of the Fire enter the Fire, a caller will cry out: "O people of Paradise! You have a covenant with Allah and He wants to fulfill it." They will say: "What is it? Has Allah not made the Balance (of our good deeds) heavy, and made our faces bright, and admitted us to Paradise and saved us from Hell?" Then the Veil will be lifted and they will look upon Him, and by Allah, Allah will not give them anything that is more beloved to them or more delightful, than looking upon Him.'" (Sahih)