Narrated by Abu Huraira (may Allah be pleased with him): The Messenger of Allah (peace and blessings be upon him) said: "Do not withhold water in excess of your need so that the grass may also be withheld."
It is narrated in another narration from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: "Do not withhold surplus water in order to prevent surplus grass."