Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Shaibani, he says: I asked Hazrat Abdullah bin Abi Awfa about domesticated donkeys. He replied: On the day of Khaybar, we were extremely hungry, and we were with the Messenger of Allah, peace and blessings be upon him. We found donkeys that had gone out of the city with the people. So we slaughtered them. Our pots were boiling when the caller of the Messenger of Allah, peace and blessings be upon him, announced: Turn over the pots, and do not eat anything from the meat of the donkeys. So we asked: Why did the Prophet, peace and blessings be upon him, declare them unlawful? The narrator says: We discussed among ourselves and said that the Prophet, peace and blessings be upon him, has declared them unlawful forever. And he, peace and blessings be upon him, declared them unlawful because they are not given as part of the khums (one-fifth share).