2 Chronicles (Author Compiled by Isaiah and Ezra from records of Nathan, Gad, Iddo, Ahijah, Jehu and others.)
20:15and he said, Be attentive, all Judah, and ye inhabitants of Jerusalem, and thou king Jehoshaphat! Thus saith Jehovah unto you: Fear not, nor be dismayed by reason of this great multitude; for the battle is not yours, but God's.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.