Musnad Ahmad 30:579

'Abd al-Razzaq narrated to us, Ma'mar informed us, from Yahya ibn Abi Kathir, from Abu Salamah, from Abu Hurayrah, who said—I do not know it except from the Prophet, may Allah bless him and grant him peace—he said: "The surplus of water shall not be withheld, so that the surplus of herbage may be withheld thereby."