Sunan Ibn Majah Book 16, Hadith 49
“The Messenger of Allah (ﷺ) said: 'Start with the horses on the day that you bring (the animals to drink).' ”
the Messenger of Allah (ﷺ) ruled concerning the irrigation of palm trees from streams, that the higher ground should be irrigated before the lower, and that the water should be allowed to reach the ankles, then released to flow the nearest lower ground, and so on, until all the fields were watered or until the water ran out.
“Every division that was allocated according to (the rules of) the Ignorance days, stands as it is, and every division that was allocated according to (the rules of) Islam, stands according to the rules of Islam.”