2 Chronicles 20:22-24

When they began singing and praising, the LORD set ambushes against the sons of Ammon, Moab, and Mount Seir, who had come against Judah; so they were struck down [in defeat]. For the sons of Ammon and Moab [suspecting betrayal] rose up against the inhabitants of Mount Seir, completely destroying them; and when they had finished with the inhabitants of Seir, they helped to destroy one another. When [the men of] Judah came to the lookout tower of the wilderness, they looked toward the multitude, and behold, they were dead bodies lying on the ground, and no one had escaped.