Every day Dom goes to a market to sell salt and flour. Every day he crosses a creek. He always brings his donkey to carry the sacks of flour and salt. One day the donkey jumped into the creek to cool off. After the donkey got out, the load lighten. The donkey was smart and he continued to do this every day. Dom was furious and wanted to teach the donkey to keep away from the creek.

How can he teach the donkey a lesson without harming it?