al-Zuhri ابن شهاب الزهري‎, محمد بن مسلم · The Book on Zakat

"The Messenger of Allah had a letter written about charity, but he had not dispatched it to his governors until he died; he kept it with him along with his sword. When he died, Abu Bakr implemented it until he died, as did Umar until he died. In it was: 'A sheep (is due) on five camels, two sheeps on ten, three sheeps on fifteen, four sheeps for twenty, a Bint Makhad on twenty-five to thirty-five. When it is more…

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.

the Messenger of Allah said: "The injuries caused by the animal are without liability, and mines are without liability, and wells are without liability, and the Khumus is due on Rikaz."

the Prophet said about Zakat on grapevines: "They are to be assessed just as the date-palm is assessed. Then its Zakat is paid in raisins just as the Zakat for the date-palm is paid in dried dates."

"The Messenger of Allah gave to me on the Day of Hunain, and he was the most hated creature to me. But he did not stop giving to me until he was the most loved creature to me."

Umar gave a horse to be used in the cause of Allah. Then he saw it being sold, so he wanted to buy it, but the Prophet said: "Do not take back what you have given in charity."