King Ying of Wei made a treaty with Marquis T'ien Mou of Ch'i, but Marquis T'ien Mou violated it. King Ying, enraged, was about to send a man to assassinate him. Kung-sun Yen, the minister of war, heard of this and was filled with shame.Go here to read the introductory post to the chapters of the Book of Chuang Tzu.
"You are the ruler of a state of ten thousand chariots," he said to the king, "and yet you would send a commoner to carry out your revenge! I beg to be given command of two hundred thousand armored troops so that I may attack him for you, make prisoners of his people, and lead away his horses and cattle. I will make him burn with anger so fierce that it will break out on his back. Then I will storm his capital, and when T'ien Chi l tries to run away, I will strike him in the back and break his spine!"
Chi Tzu, hearing this, was filled with shame and said, "If one sets out to build an eighty-foot wall, and then, when it is already seven-tenths finished, deliberately pulls it down, the convict laborers who built it will look upon it as a bitter waste. Now for seven years we have not had to call out the troops, and this peace has been the foundation of your sovereignty. Kung-sun Yen is a troublemaker - his advice must not be heeded!"
~ Burton Watson translation via Terebess Asia Online ~