Abdullah bin Wahb عبد الله بن وهب بن مسلم القرشي · The Book on Zakat

that the Prophet said: "When you pay the Zakat you have fulfilled what is required of you."

the Messenger of Allah instituted the Ushr of what was watered by the heavens and steams, or through natural channels, and half of the Ushr for what is watered by irrigation.