As soon as the drums of the Qi army rang, Duke Zhuang of Lu was ready to beat them, and immediately stopped him and said, "Not yet, wait." Soon, the Qi army drummed again, but Cao Gui still stopped the Lu army from fighting.
After the Qi army beat the drums three times, let Duke Zhuang of Lu beat the drums. The soldiers of the Lu army, who had been waiting for a long time, rushed to the enemy like a storm, killing the Qi army in flight and fleeing everywhere.
After the victory of LuJun, Zhuang Gong asked Cao Gui, why do you want to command? Cao Gui said that fighting depends on morale. The soldiers were full of morale when they beat the drum for the first time, and their morale began to decline when they beat the drum for the second time. By the third time, morale was gone. The Qi army beat the drums three times, and the soldiers were exhausted and relaxed, but we only beat the drums once, and the morale was booming, so naturally we could beat them.