Sunan An-Nasa'i - سنن النسائي
23. The Book of Zakah - كتاب الزكاة
25) Chapter: On What One-Tenth Is Due, And on What One-Half Of One-Tenth Is Due
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."
25) باب مَا يُوجِبُ الْعُشْرَ وَمَا يُوجِبُ نِصْفَ الْعُشْرِ
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 .