Musnad Ahmad 3504

It was narrated from Ibn ‘Abbas (رضي الله عنه) that he said: The Prophet (ﷺ) came to Zamzam and we drew a bucket for him and he drank, then he ejected some water back into it, then we emptied it into Zamzan. Then he said: "Were it not that you would be overwhelmed at (the well), I would have drawn it with my own hands.”