One day, a man of the State of Chu was crossing a river by boat. Due to carelessness, his sword which hung at his side fell into the water. Not in the least worried, he slowly took out a small knife and cut a mark on the side of the boat.
Someone on the boat asked him:
"Why don't you jump into the water at once to fish for your sword? What's the use of making this mark on the side of the boat?"
He pointed to the mark on the side of the boat, saying unhurriedly:
"There is no need to worry. My sword fell into the river at this marked place. As soon as the boat reaches the dock and pulls in to shore, I will jump down from here to retrieve my sword."