Tha'labah bin Abi Malik heard from his elders that there was a man of Quraysh who had a share in Banu Qurayzah. He came to the Messenger of Allah (peace and blessings be upon him) with a dispute over the torrent channel of Mahzur, whose water they used to share. He (peace and blessings be upon him) judged between them: "When the water reaches the ankles, the upper one should not withhold it from the lower one."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11857