Sahih Muslim 5011

Sulaiman Shaibini reported:I heard Abdullah b. Abu Aufa say: We were smitten with hunger during the nights of Khaibar. On the Day of Khaibar, we fell upon domestic asses and we slaughtered them, and when our earthen pots boiled with them, the announcer of Allah's Messenger (ﷺ) made an annoancement that the earthen pots should be turned over, and nothing should be eaten of the flesh of the domestic asses. Some of the people said that Allah's Messenger (ﷺ) had forbidden (the use of this flesh) for one-fifth (due to the State) has not been paid, while others said: He prohibited it for ever