That when they were in the company of the Prophet, they got some donkeys which they (slaughtered and) cooked. Then the announcer of the Prophet (ﷺ) said, "Turn the cooking pots upside down (i.e. throw out the meat).
Sahih al-Bukhari Book 64, Hadith 261
← Previous Hadith We where afflicted with severe hunger on the day of Khaibar. While the cooking pots were boiling and some of the food was well-cooked, the announcer of the Prophet (ﷺ) came to say, "Do not eat anything the donkey-meat and upset the cooking pots." We then thought that the Prophet (ﷺ) had prohibited such food because the Khumus had not been taken out of it. Some others said, "He prohibited the meat of donkeys from the point of view of principle, because donkeys used to eat dirty things."

Sahih al-Bukhari Book 64, Hadith 260 Next Hadith → On the day of Khaibar when the cooking pots were put on the fire, the Prophet (ﷺ) said, "Turn the cooking pots upside down."

Sahih al-Bukhari Book 64, Hadith 262