2 Chronicles 20:21-22

21And when he had consulted with the people, he appointed singers unto Yhwh, and that should praise the beauty of holiness, as they went out before the army, and to say, Praise Yhwh; for his mercy endureth for ever.1

22And when they began to sing and to praise, Yhwh set ambushments against the children of Ammon, Moab, and mount Seir, which were come against Judah; and they were smitten.234