2 Chronicles 20:21-24

21And when he had taken counsel with the people, he appointed them that should sing unto the LORD, and praise the beauty of holiness, as they went out before the army, and say, Give thanks unto the LORD; for his mercy endureth for ever.

22And when they began to sing and to praise, the LORD set liers in wait against the children of Ammon, Moab, and mount Seir, which were come against Judah; and they were smitten.

23For the children of Ammon and Moab stood up against the inhabitants of mount Seir, utterly to slay and destroy them: and when they had made an end of the inhabitants of Seir, every one helped to destroy another.

24And when Judah came to the watch-tower of the wilderness, they looked upon the multitude; and, behold, they were dead bodies fallen to the earth, and there were none that escaped.