Sayyiduna al-Bara and Sayyiduna Abdullah bin Abi Awfa (may Allah be pleased with them both) say that on the day of Khaybar they came upon donkeys, which they cooked; then the caller of the Prophet (peace and blessings be upon him) announced: "Let the pots be overturned."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19456