Musnad Ahmad 32:784

Hajjaj narrated to us, Sulayman—meaning Ibn al-Mughirah—narrated to us, from Thabit, from Anas ibn Malik, who said: I said: "Narrate to us something you witnessed of these wonders, do not narrate to us about it from someone else." He said: The Messenger of Allah (ﷺ) prayed Dhuhr, and he sat on the seats upon which Jibril (peace be upon him) used to come to him. He said: Then Bilal came and informed him of the time for the Asr prayer. He said: "Whoever has family in Medina, let him attend to his need and perform wudu." There remained some people from the Muhajirun who had no families in Medina. He said: A wide vessel was brought to the Messenger of Allah (ﷺ), in the bottom of which was some water. He said: The Messenger of Allah (ﷺ) placed his palm in the vessel, but his palm could not fit, so he placed these four fingers of his, then said: "Come near and perform wudu." He said: So they performed wudu, until not one of them remained except that he had performed wudu. We said: "O Abu Hamzah, how many do you think they were?" He said: "Between seventy and eighty."