Muwaththa' Malik · #608
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ الثِّقَةِ، عِنْدَهُ عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، وَعَنْ بُسْرِ بْنِ سَعِيدٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " فِيمَا سَقَتِ السَّمَاءُ وَالْعُيُونُ وَالْبَعْلِ الْعُشْرُ وَفِيمَا سُقِيَ بِالنَّضْحِ نِصْفُ الْعُشْرِ " .
English
Yahya related to me from Malik from a reliable source from Sulayman ibn Yasar and from Busr ibn Said that the Messenger of Allah, may Allah bless him and grant him peace, said, "On land that is watered by rain or springs or any natural means there is (zakat to pay of) a tenth. On irrigated land there is (zakat of) a twentieth (to pay)