It was narrated that 'Abdullah bin Awfa said: "On the Day of khaiber we caught some donkeys outside the village and we cooked them. Then the caller of the Prophet called out: “The Messenger of Allah has forbidden the flesh of donkeys, so turn over your cooking pots with whatever is in them.' So we turned them over”"
SahihSahihSahih - Agreed UponBook 42 · Hadith 77