I do not know it except from the Prophet ﷺ, who said, "Surplus water must not be withheld in order to withhold thereby the surplus pasture."
حدثنا عبد الرزاق أخبرنا معمر عن يحيى بن أبي كثير عن أبي سلمة
لا أعلمه إلا عن النبي ﷺ قال لا يمنع فضل ماء ليمنع به فضل الكلإ
Its chain of transmission is sahih, and the doubt about its being raised to the Prophet here does not affect its soundness. It has been established from Abu Hurairah, raised to the Prophet, through more than one route. It has already appeared at 7320 from the narration of Abu Zinad, from Araj, from Abu Hurairah, raised to the Prophet, and we pointed out some of its routes there.