Taking a Knife on Behalf of Others

During the Period of Three States, Cao Cao, Emperor Wu of Wei, would summon the messenger from the Huns. He worried that his ugly appearance was insufficient to deter the remote small country, so he appointed Minister Cui Jigui, who had an imposing appearance, to replace him and sit on his normal place. Cao Cao dressed himself up as a guard, standing by with a sword.

After the meeting, Cao Cao sent an underling to ask the messenger in private,“What's your opinion on the King?”

The messenger answered,“the King was elegant and graceful, but the guard, who took a sword, was likely to be a true hero.”

We later describe somebody who ghostwrites for other people as a person taking a sword; we can also use this idiom to describe somebody who does things on behalf of others.

It tells us that such tricks are very popular in this world. We must be perceptive of the slightest like the Hun messenger in order to avoid being cheated.