2 Chronicles 20:22-23

²²When they began to sing and to praise, Yahweh set liers-in-wait against the children of Ammon, Moab, and Mount Seir, who had come against Judah; and they were struck. ²³For the children of Ammon and Moab stood up against the inhabitants of Mount Seir, utterly to kill and destroy them: and when they had made an end of the inhabitants of Seir, everyone helped to destroy another.