It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when the Prophet (peace and blessings be upon him) would dispatch any of his armies, he would say: "Set out in the name of Allah, fight those who disbelieve in Allah, do not be treacherous, do not commit breach of trust regarding the spoils of war, do not mutilate the dead bodies, and do not kill children or religious leaders."