21 And when he had consulted with the people, he appointed some to sing unto the LORD and to praise in the beauty of holiness, while the army went out and to say, Praise the LORD, for his mercy [endures] for ever.

22 And when they began to sing and to praise, the LORD set the sons of Moab and those of Mount Seir to ambush the sons of Ammon, who were coming against Judah; and they smote [one another].