Musnad Ahmad 5:801

'Affan narrated to us, Abu 'Awanah narrated to us, from 'Uthman ibn al-Mughirah, from Abu Sadiq, from Rabi'ah ibn Najidh, from 'Ali, may Allah be pleased with him, who said: The Messenger of Allah (ﷺ) gathered—or the Messenger of Allah (ﷺ) invited—the Banu 'Abd al-Muttalib. Among them was a group, all of whom would eat a young weaned camel and drink a *faraq* (a large measure). He said: So he prepared for them a *mudd* (a small measure) of food, and they ate until they were full. He said: And the food remained as it was, as if it had not been touched. Then he called for a drink, and they drank until they were quenched, and the drink remained as if it had not been touched—or not drunk from. Then he said: "O Banu 'Abd al-Muttalib, I have been sent to you specifically and to the people generally. You have seen of this sign what you have seen, so which of you will pledge allegiance to me to be my brother and my companion?" He said: No one stood up to him. He said: So I stood up to him, and I was the youngest of the people. He said: So he said: "Sit down." He said: Three times, every time I would stand up to him, he would say to me: "Sit down," until, on the third time, he struck his hand upon my hand.