In the spring of the tenth year of Duke Zhuang of Lu, the Qi army attacked Lu. Duke Zhuang of Lu can fight. Cao Gui asked to meet Duke Zhuang of Lu. His fellow countryman said, "A person with a high position in the war can plan for himself. Why do you participate?" Cao Gui said: "People at high altitudes are short-sighted and cannot think ahead." So he went to North Korea to see Duke Zhuang of Lu. Cao Gui asked, "What are you fighting for?" Duke Zhuang of Lu said, "Food and clothing are a kind of livelihood, which cannot be enjoyed exclusively, but must be given to the surrounding ministers." Cao Gui replied: "These small favors can't be spread to the people, and the people won't listen to you." Duke Zhuang of Lu said: "I (never) dare to falsely report the number of cattle, sheep, jade and silk sacrificed to the gods." I must be honest and trustworthy. " Cao Gui said, "This is only a small contribution. You cannot convince the gods. God will not bless you. " Lv Zhuanggong said: "Although we can't understand all the cases clearly, we must handle them reasonably." Cao Gui replied, "This is the only thing we can do. We can fight a war under this condition. If you fight, please allow me to go with you. " Duke Zhuang of Lu and he * * * sat in a chariot and fought the Qi army in the ladle. Duke Zhuang of Lu will order drums to advance. Cao Gui said, "Not now." Wait until the Qi army drums three times. Cao Gui said, "You can beat the drums." The Qi army was defeated. Duke Zhuang of Lu wants to order horses to chase the Qi army. Cao Gui said, "Not yet." Say that finish, he got out of the chariot, looked at the trace of Qi's wheels, boarded the chariot again, propped up the crossbar in front of the chariot and watched the formation of Qi. He said, "We can pursue it." So I chased the Qi army. After defeating the Qi army, Duke Zhuang of Lu asked him why he did it. Cao Gui replied, "Fighting depends on courage and fearlessness. Playing drums for the first time can boost morale. After the second drum beat, the morale of soldiers began to decline, and after the third drum beat, they were even more exhausted. Their morale was gone, and our army was full of morale, so we defeated them. In a big country like Qi, it is difficult to speculate on their situation, for fear that they will set an ambush. I saw the traces of their wheels scattered and the flags fell, so I decided to chase them. "