Musannaf Ibn Abi Shayba 16:201

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mansur, from Mujahid, from Ali al-Azdi, who said: I said to Ibn Umar: "We travel and pass by shepherds, children, and women, and they feed us meat, and we do not know what they have withheld (from the name of Allah)." He said: "If the Muslims feed you, then eat."