春秋時齊景公有三位勇猛無比的手下，分別叫做公孫接、田開疆和古治子。
有一天，宰相晏嬰從他們面前經過，照禮他們要起來行禮，他們卻坐著一動也不動，晏嬰當場沒說話，接著便馬上告訴齊景公這件事，並且勸說：「這三個人仗著自己立下不少大功勞，現在已經是目中無人，今天只是對我無禮，難保改天不會對大王無禮，我建議儘快將這三人除去，以免後患無窮。」
景公向來十分敬重晏嬰的話，當場點頭表示同意，不過馬上露出面有難色說：「可是，怎樣去除呢？沒有人打得過他們；派人暗殺行刺，也不是他們的對手。」晏嬰聽完說：「我早料到了，我已經想好對付他們的計謀了。」，便將「二桃殺三士」之計告訴了景公。只有兩個桃子的賞賜，讓他們三人「計功而食桃」。結果是三人爭得不可開交，公孫接先說：「我的功勞最大，我空手制服野豬及活捉老虎。」便拿走一個桃子，田開疆說：「我曾用長矛擊退一整隊敵人。」也拿走一個桃；古治子氣得滿臉通紅說：「難道我的功勞就比你們小嗎？」便抽出劍做決鬥狀，沒想到其他兩個人竟然把桃子放回桌子，說：「我們應該重榮譽怎麼可以搶功，真是太慚愧了！」說完便刎頸而死，古治子看到也跟著刎頸，晏子不費吹灰之力，便剷除大患。「二桃殺三士」並非因為桃子有毒而致人死命，而是政治權術中的殺人工具，也可以把這件事稱作「借桃殺人」。
三十六計之第三計：借刀殺人
指以冠冕堂皇的藉口，假借他人之手來達到自己的目的，「刀」只是一種比喻。
During the Spring and Autumn Period, there were three fearless warriors in Ci by the name of Gong Sun Jie, Tian Kai Jiang and Gu Jhih Zih.
One day, the prime minister Yan Ying walked past the three generals. Court protocol demands that they rise and bow to Yan Ying as a matter of courtesy. However, the three of them just sat there without acknowledging Yan Ying's presence. Yan Ying said nothing on the spot. But afterwards, he told the king of Ci about this incident and advised him, ''These three generals have become arrogant because they have accomplished much on the battlefield. Today they only showed disrespect towards me. But who knows whether or not they will show disrespect towards your Majesty in the future. I suggest that they be removed as soon as possible so as to avoid any future troubles.'' The king of Ci,Jing Gong,had a high respect for Yan Ying and always followed his advice. So he agreed with him, but he added, ''But how? No one is strong enough to beat them. Nor is anybody capable of assassinating them.''Yan Ying replied, ''I have already figured out how to deal with them.'' He then told Jing Gong his plan to kill three warriors with two peaches. Two peaches were to be awarded to the two who deserved it the most.
The three of them argued fiercely in the beginning. Gong Sun Jie said first, ''I caught a wild pig and a tiger alive with my bare hands. So I deserve the most.''Then he took one peach. Then Tian Kai Jiang said, ''I defeated a whole squad of soldiers with my spear.''Then took the other peach, too. Gu Jhih Zih turned red with anger, ''Am I less worthy than you two? ''He pulled his sword and challenged the other two to a duel. To everybody's surprise, the other two put the peaches back onto the table and said, ''Honor is more important than fighting over the rewards. We should be ashamed of ourselves.'' That said, Gong Sun Jie and Tian Kai Jiang slit their own throats with their swords and died. Having watched this, Gu Jhih Zih, too, killed himself the same way. Thus Yan Ying was able to remove three potential threats to the country of Ci without lifting a finger.
Strategy 3: Kill with a Borrowed Sword
Openly use another to achieve one's purpose. ''Sword'' is used here as a metaphor for the means to an end.
