Sunan Ibn Majah, Chapter: The Chapters on Drinks

"The Messenger of Allah (saw) entered upon a man among the Ansar when he was watering his garden. The Messenger of Allah (saw) said to him: 'If you have any water that has been kept overnight in a water skin, then give us some to drink, otherwise we will drink by putting out mouths in the basin.' He said: 'I have water that has been kept in a water skin. So he went and we went with him, to the shelter, where he milked a sheep for him and (mixed it with) the water that had been kept overnight in a water skin. He drank from it, then he did likewise for his Companion who was with him."