A father and son lived on the mountain, and they had to drive the ox cart down the mountain every day to sell firewood. The father was more experienced and knew how to benefit himself while benefiting others. He would sit in a chair and control the ox cart as it drove down the bumpy mountain road with many sharp turns. The son had good eyesight and would always remind his father when a turn was coming: "Father, there's a turn ahead!"
One day, the father was too sick to go down the mountain, so the son went alone. When the ox cart reached a turn, the ox refused to turn. The son tried everything - pushing and pulling the ox, even tempting it with grass - but the ox wouldn't budge.
The son couldn't figure out what was wrong. Finally, he had only one idea left. After making sure no one was around, he leaned close to the ox's ear and shouted loudly: "Father, turn!"
The ox responded immediately and turned.