2 Chronicles 20:17-20 ~ The Amplified Bible

You shall not need to fight in this battle; take your positions, stand still, and see the deliverance of the Lord [Who is] with you, O Judah and Jerusalem. Fear not nor be dismayed. Tomorrow go out against them, for the Lord is with you.  And Jehoshaphat bowed his head with his face to the ground, and all Judah and the inhabitants of Jerusalem fell down before the Lord, worshiping Him. And some Levites of the Kohathites and Korahites stood up to praise the Lord, the God of Israel, with a very loud voice.

 And they rose early in the morning and went out into the Wilderness of Tekoa; and as they went out, Jehoshaphat stood and said, Hear me, O Judah, and you inhabitants of Jerusalem! Believe in the Lord your God and you shall be established; believe and remain steadfast to His prophets and you shall prosper.When he had consulted with the people, he appointed singers to sing to the Lord and praise Him in their holy [priestly] garments as they went out before the army, saying, Give thanks to the Lord, for His mercy and loving-kindness endure forever!

 And when they began to sing and to praise, the Lord set ambushments against the men of Ammon, Moab, and Mount Seir who had come against Judah, and they were [self-] slaughtered.