Musnad Ahmad 850:15

'Affan narrated to us, Jarir ibn Hazim narrated to us, Ya'la ibn Hakim narrated to me, from Abu Labid, who said: We went on a military expedition with 'Abd al-Rahman ibn Samurah to Kabul. He said: The people obtained spoils of war and plundered them. 'Abd al-Rahman ibn Samurah ordered a crier to make an announcement, so he announced it, and the people gathered. He said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: "Whoever plunders is not one of us." Return them. So they returned them, and he divided them among them equally.