Musnad Ahmad 696:11

'Affan narrated to us, Hammad narrated to us, Thabit informed us, from 'Abd al-Rahman ibn Abi Layla, from Suhayb, that the Messenger of Allah (peace and blessings of Allah be upon him) recited this verse: "For those who have done good is the best [reward] and extra" [Yunus: 26]. He said: "When the people of Paradise enter Paradise, and the people of the Fire enter the Fire, a caller will call out: 'O people of Paradise, you have a promise from Allah that He wishes to fulfill for you.' They will say: 'And what is it? Has He not made our scales heavy, whitened our faces, admitted us into Paradise, and saved us from the Fire?'" He said: "Then the veil will be lifted for them, and they will look at Him." He said: "By Allah, He has not given them anything more beloved to them than looking at Him, nor anything more delightful to their eyes."