Musnad Abu Ya'la al-Mawsili 159:37

Bishr narrated to us, Abd al-Rahman narrated to us, from his father, from Abd al-Rahman al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The surplus of water shall not be withheld, so that the pasture may be withheld by it."