Sahih al-Bukhari, Book 90, Hadith 9 (In-Book) ⓘ
Narrated Abu Huraira: Allah's Messenger said, "One should not prevent others from watering their animals with the surplus of his water in order to prevent them from benefiting by the surplus of grass."
حَدَّثَنَا إِسْمَاعِيلُ، حَدَّثَنَا مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ يُمْنَعُ فَضْلُ الْمَاءِ لِيُمْنَعَ بِهِ فَضْلُ الْكَلإِ " .
also referenced under: Hadith 6962 (DarusSalam) & Volume 9, Book 86, Hadith 92 (USC-MSA)