Sunan an-Nasa'i, Hadith 2490 ⓘ
It was narrated that Mu'adh said: "The Messenger of Allah sent me to Yemen and he commanded me to take one-tenth of whatever is irrigated by the sky, and half of one-tenth of whatever is irrigated by means of buckets."
أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي بَكْرٍ، - وَهُوَ ابْنُ عَيَّاشٍ - عَنْ عَاصِمٍ، عَنْ أَبِي وَائِلٍ، عَنْ مُعَاذٍ، قَالَ بَعَثَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم إِلَى الْيَمَنِ فَأَمَرَنِي أَنْ آخُذَ مِمَّا سَقَتِ السَّمَاءُ الْعُشْرَ وَفِيمَا سُقِيَ بِالدَّوَالِي نِصْفَ الْعُشْرِ .
also referenced under: Book 23, Hadith 0 (In-Book) & Volume 3, Book 23, Hadith 2492 (DarusSalam)