Musnad Ahmad 830:72

'Abd al-Samad narrated to us, Hammad—meaning Ibn Salamah—narrated to us, 'Ali ibn Zayd narrated to us, from 'Abd al-Rahman ibn Abi Bakrah, who said: I arrived with my father to Mu'awiyah ibn Abi Sufyan, and we were brought in to him. He said: "O Abu Bakrah, narrate to me something you heard from the Messenger of Allah (peace and blessings of Allah be upon him)." He said: "The Messenger of Allah (peace and blessings of Allah be upon him) used to like a righteous dream and would ask about it. One day, the Messenger of Allah (peace and blessings of Allah be upon him) said: 'Which of you has seen a dream?'" A man said: "I, O Messenger of Allah. I saw as if a scale was lowered from the sky. You were weighed against Abu Bakr, and you outweighed Abu Bakr. Then Abu Bakr was weighed against 'Umar, and Abu Bakr outweighed 'Umar. Then 'Umar was weighed against 'Uthman, and 'Umar outweighed 'Uthman. Then the scale was raised." The Messenger of Allah (peace and blessings of Allah be upon him) was distressed by that, and he said: "A caliphate of prophethood, then Allah gives the kingdom to whom He wills." 'Affan said in it: "He was distressed by it," and Hammad said: "That distressed him."