Musnad Ahmad 1018:55

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Simak ibn Harb, who said: I heard a man from Banu Layth say: Some of the companions of the Prophet, may Allah bless him and grant him peace, took me captive, and I was with them. They obtained some sheep, so they plundered them and cooked them. He said: Then I heard the Messenger of Allah, may Allah bless him and grant him peace, say: "Indeed, plundering (al-nahba) is not lawful, so overturn the cooking pots."