Sami Maula Abi Bakr bin 'Abdur Rahman سمي مولى أبي بكر بن عبد الرحمن بن الحارث · The Book of Zakah

'Umar give a house in charity for the sake of Allah, the Mighty and Sublime, and he found it being offered for sale after that. He wanted to buy it, then he went to the Messenger of Allah and asked him about that. The Messenger of Allah said: "Do not take back what you have given in charity."

That the Messenger of Allah told 'Attab bin Usaid to estimate the (harvest of) grapes, and to pay Zakah in raisins, just as the Zakah on date palms is given in died dates.