Sayyiduna Tha'labah bin al-Hakam (may Allah be pleased with him) narrates: On the day of Khaybar we got some sheep and goats, and we plundered them. Then the Messenger of Allah (peace and blessings be upon him) came while their cooking pots were boiling. The people said: This is plunder. He (peace and blessings be upon him) said: "Overturn the cooking pots, for plunder is not lawful."
Hadith Referenceالمعجم الكبير للطبراني / باب الثاء / 1361