2 Chronicles 20:20-23

20Early in the morning they left for the Desert of Tekoa. As they set out, Jehoshaphat stood and said, “Listen to me, Judah and people of Jerusalem! Have faith in the LORD your God and you will be upheld; have faith in his prophets and you will be successful.”

21After consulting the people, Jehoshaphat appointed men to sing to the LORD and to praise him for the splendor of his Or him with the splendor of holiness as they went out at the head of the army, saying: “Give thanks to the LORD, for his love endures forever.” 22As they began to sing and praise, the LORD set ambushes against the men of Ammon and Moab and Mount Seir who were invading Judah, and they were defeated.

23The Ammonites and Moabites rose up against the men from Mount Seir to destroy and annihilate them. After they finished slaughtering the men from Seir, they helped to destroy one another.