On the day of Khaybar, we caught some donkeys that had wandered out of the village and cooked them. Then a caller of the Prophet ﷺ announced, "The Messenger of Allah ﷺ has forbidden the flesh of donkeys, so empty the pots along with their contents." So we emptied them.
أخبرنا محمد بن عبد الله بن يزيد المقرئ قال حدثنا سفيان عن أبي إسحق الشيباني
أصبنا يوم خيبر حمرا خارجا من القرية فطبخناها فنادى منادي النبي ﷺ إن رسول الله ﷺ قد حرم لحوم الحمر فأكفئوا القدور بما فيها فأكفأناها
Bukhari narrated it in the chapter on the fifth of spoils, in the section on what one obtains of food in enemy territory, hadith no. 3155, and Muslim, in the chapters on hunting and slaughtered animals, in the section on the prohibition of eating the meat of domestic donkeys, hadith no. 1937, from the hadith of Shaybani through this same chain. It is also found in Al-Kubra, hadith no. 4851.