Musannaf Ibn Abi Shayba 13:1194

Abu Bakr narrated to us, he said: Ibn Abi Za’idah narrated to us, from Hajjaj, from al-Hakam, who said: A mule was found in al-Nahrayn, and each group brought evidence that it belonged to them. Abdullah ibn Utbah judged that it belonged to the one in whose possession it was.