2 Chronicles 20:21 RSV

[21] And when he had taken counsel with the people, he appointed those who were to sing to the LORD and praise him in holy array, as they went before the army, and say, "Give thanks to the LORD, for his steadfast love endures for ever." 22 And when they began to sing and praise, the LORD set an ambush against the men of Ammon, Moab, and Mount Se′ir, who had come against Judah, so that they were routed.