The Messenger of Allah ﷺ ruled regarding the flow of Mahzur stream that the upper land takes precedence over the lower. The upper land is to be watered until the water reaches the ankles, then it is released to the land below it.
حدثنا إبراهيم بن المنذر الحزامي حدثنا زكريا بن منظور بن ثعلبة بن أبي مالك حدثني محمد بن عقبة بن أبي مالك
قضى رسول الله ﷺ في سيل مهزور الأعلى فوق الأسفل يسقي الأعلى إلى الكعبين ثم يرسل إلى من هو أسفل منه
[Hasan]. Busiri said, "The isnad of his hadith is daif. Zakariya bin Mandhur is agreed upon as daif, and his teacher is obscure (mastur)."Ibn Abu Asim narrated it in Al-Ahad wal-Mathani (4/215, no. 2200), and Tabarani in Al-Kabir (2/86, no. 1387), through the hadith of Yaqub bin Humayd bin Kasib, from Ishaq bin Ibrahim bin Saeed al-Sawwaf al-Madani, the freedman of Mazina, from Safwan bin Salim, from Thalaba, with a similar meaning.Ishaq is "layyin al-hadith" (weak in transmission) as stated in Taqrib, and Abu Zura and Abu Hatim and others declared him daif, as mentioned in Tahdhib and elsewhere. So the chain is daif.There is another route for it in Tabarani, no. 1386, which contains Muhammad bin Ishaq, who is truthful but known for tadlis (concealment in transmission), and he narrated it using "an" (a formula that may indicate concealment).The hadith has many corroborating witnesses in Abu Dawud, no. 3638, and elsewhere. See also the following hadith.