Psalms (Author Moses, David, Solomon, Asaph, Heman, Ethan, sons of Korah, compiled by Ezra)
32:9Be ye not as the horse, or as the mule, which have no understanding: whose mouth must be held in with bit and bridle, lest they come near unto thee.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.