2 Chronicles 20:18-22
English Standard Version
Chapter 20
18Then Jehoshaphat bowed his head with his face to the ground, and all Judah and the inhabitants of Jerusalem fell down before the Lord, worshiping the Lord. 19And the Levites, of the Kohathites and the Korahites, stood up to praise the Lord, the God of Israel, with a very loud voice.
20And they rose early in the morning and went out into the wilderness of Tekoa. And when they went out, Jehoshaphat stood and said, "Hear me, Judah and inhabitants of Jerusalem! Believe in the Lord your God, and you will be established; believe his prophets, and you will succeed."
21And when he had taken counsel with the people, he appointed those who were to sing to the Lord and praise him in holy attire, as they went before the army, and say, "Give thanks to the Lord, for his steadfast love endures forever."