Musnad Ahmad 658:117

Hashim narrated to us, Sulayman narrated to us, from Humayd, from Yunus, from al-Bara’ who said: We were with the Messenger of Allah (peace and blessings of Allah be upon him) on a journey, and we came upon a *raki* (well) of *dhimmah*, meaning one with little water. He said: Six of us descended into it, and I was the sixth of them, drawing water. A bucket was lowered to us. He said: The Messenger of Allah (peace and blessings of Allah be upon him) was at the edge of the well. We filled it halfway, or nearly two-thirds of it, and it was raised to the Messenger of Allah (peace and blessings of Allah be upon him). Al-Bara’ said: I looked at my vessel, hoping to find something to put in my throat, but I found nothing. Then the bucket was raised to the Messenger of Allah (peace and blessings of Allah be upon him), and he dipped his hand into it and said what Allah willed for him to say. Then the bucket was returned to us with what was in it. He said: I saw one of us pulling it out with a garment for fear of drowning. He said: Then it flowed, meaning it ran like a river.