2 Chronicles 20:22-23

²²And when they began to sing and praise, the LORD set an ambush against the men of Ammon, Moab, and Mount Se'ir, who had come against Judah, so that they were routed. ²³For the men of Ammon and Moab rose against the inhabitants of Mount Se'ir, destroying them utterly, and when they had made an end of the inhabitants of Se'ir, they all helped to destroy one another.