English Original
During the Spring and Autumn Period, the armies of Qi and Lu faced each other. When Qi beat the war drums for the first time to signal battle, the ruler of Lu wished to attack immediately. His advisor, Cao Gui, advised, "We should wait until the third drum roll, sire."
After Qi had beaten the drums three times, the Lu army attacked and achieved victory. After the battle, the king asked Cao Gui for the reasoning behind his unusual advice.
Cao Gui explained, "Fighting requires spirit. The enemy's spirit was at its peak with the first drum roll, diminished with the second, and completely exhausted by the third. We attacked when their spirit was spent. That is why we won."
This idiom has come to mean accomplishing a task in one sustained, vigorous effort.
中文翻译
春秋时期，齐国和鲁国的军队对阵。当齐国第一次击鼓进军时，鲁国国君想要立刻出击。他的谋士曹刿建议道：“我们应该等到第三次击鼓，陛下。”
在齐国击鼓三次之后，鲁军发动进攻并取得了胜利。战后，鲁君询问曹刿提出这个不寻常建议的原因。
曹刿解释道：“作战靠的是士气。敌军的士气在第一次击鼓时最旺盛，第二次击鼓时就减弱了，到第三次击鼓时已完全耗尽。我们在他们士气耗尽时发动进攻，所以取得了胜利。”
这个成语后来意指做事要趁着一开始劲头足的时候，一口气把它完成。