2 Chronicles 20:21-23

Jehoshaphat listened to the people’s advice. Then he chose men to be singers to the LORD, to praise him because he is holy and wonderful. As they marched in front of the army, they said, “Thank the LORD, because his love continues forever.” As they began to sing and praise God, the LORD set ambushes for the people of Ammon, Moab, and Edom who had come to attack Judah. And they were defeated. The Ammonites and Moabites attacked the Edomites, destroying them completely. After they had killed the Edomites, they killed each other.