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