2 Chronicles 20:12, 15, 17, 20-21

O our God, wilt thou not judge them? for we have no might against this great company that cometh against us; neither know we what to do: but our eyes are upon thee.

and he said, Hearken ye, all Judah, and ye inhabitants of Jerusalem, and thou king Jehoshaphat, Thus saith the LORD unto you, Be not afraid nor dismayed by reason of this great multitude; for the battle is not your's, but God's.

Ye shall not need to fight in this battle: set yourselves, stand ye still, and see the salvation of the LORD with you, O Judah and Jerusalem: fear not, nor be dismayed; to morrow go out against them: for the LORD will be with you.

And they rose early in the morning, and went forth into the wilderness of Tekoa: and as they went forth, Jehoshaphat stood and said, Hear me, O Judah, and ye inhabitants of Jerusalem; Believe in the LORD your God, so shall ye be established; believe his prophets, so shall ye prosper. And when he had consulted with the people, he appointed singers unto the LORD, and that should praise the beauty of holiness, as they went out before the army, and to say, Praise the LORD; for his mercy endureth for ever.