A preacher was wanting to buy a horse to make his visits in a small farming town. He was sent to an old farmer that had a very unique horse. The preacher wanted to try the horse out, so the old farmer told him what made the horse unique. "If you want the horse to go forward," the old farmer said, "shout Praise the Lord. If you want the horse to stop, yell Hallelujah." The preacher mounted the horse and shouted Praise the Lord. The horse started running. The preacher was so excited that he let the horse continue to run until he saw a great cliff ahead. He yelled stop, halt, quit; but the horse kept running. The preacher finally remembered the words of the old farmer and yelled Hallelujah just in time. The horse skidded to a halt on the very edge of the cliff. The preacher took off his hat, wiped his brow, and said, "Praise the Lord."
From the Free Republic page.
LOL! I remember my dad's friend telling that joke when I was little.