Retreating about Thirty Miles as Condition For Peace
　　During the Spring and Autumn Period (770-476 B.C.), Duke Xian of the State of Jin Killed the crown prince Sheng because he had heard slanders¹ about Sheng and believed them. He also sent his men to arrest Chong Er, Shen Sheng and believed them. He also sent his men to arrest Chonh Er, Shen Sheng's brother. Hearing the news, Chong Er escaped from the state of Jin, remaining a fugitive² for more than ten years.
　　After innumerable hardships, Chong Er arrived at the State of Chu at last. King Cheng of the State of Chu treated him with high respect as he would have treated the ruler of a state, believing that he would have a vright fuure.
　　One day, King Cheng of the State of Chu gave a banquet in honoudr of Chong Er. Suddenly, amid the harmonious³ atmosphere of drinking and talking, King Cheng of the State of Chu asked Chong Er. "How will you repay me when you return to the State of Jin and become its ruler one day?" After thinking for a moment, Chong Er said, "You have plenty of beauties and attendants as well as jewelry⁴ and silk cloth, and the state of Chu abounds⁵ in rare brides and animals. What treasure can the State of Jin boast having to present to your majesty⁶?" King Cheng of the State of Chu said, "You are too modest. Nevertheless, you still have to show your gratitude⁷ to me in one way or another, I presume?" Smiling, Chong Er answered, "If I should be fortunate enouge to return to the State of Jin and become its ruler, the State of Jin would be friendly to the State of Chu. If, one day, there should be a war between the two states, I would definitely order my troops to retreat three SHE (one SHE is equivalent to thirty LI. The LI is a Chinese unit of length equivalent to 1/2 kilometre. And, therefore, three SHE is about thirty miles.) as a condition for peace. If, under that condition, you were still not reconciled, I would have to fight with you."
　　Four years later, as might be expected, Chong Er returned to the State of Jin and became its ruler. He was none other than Duke Wen of the State of Jin famous in ancient Chinese history. Ruled by him, the State of Jin became increasingly powerful.
　　In the year 533 B.C., the Chu troops and the Jin troops confronted each other in a battle. Faithful to his promise, Duke Wen of the State of Jin ordered his troops to retreat about thirty miles. After retreating, the Jin troops were stationed at Chengpu. Seeing that the Jin troops were retreating, the Chu troops thought that the enemy troops were afraid, and began chasing them. Taking advantage of the Chu troops' arrogance⁸ and their talking the Jin troops lightly, the Jin troops concentrated their forces and inflicted⁹ a crushing defeat on the Chu troops, thus winning the victory of the battle of Chengpu.
　　This set phrase, "retreating about thirty miles as a condition for peace," is derived¹⁰ from the Chapter "The Twenty-second Year of Duke Xi" in ZuoZhuan, the famous commentary by Zuo Qiuming on The spring and Autumn Annals. The idea of this set phrase is to give way to somebody in order to avoid a conflict.

　　春秋时候，晋献公听信谗言，杀了太子申生，又派人捉拿申生的弟弟重耳。重耳闻讯，逃出了晋国，在外流忘十几年。
　　经过千幸万苦,重耳来到楚国。楚成王认为重耳日后必有大作为，就以国群之礼相迎，待他如上宾。
　　一天，楚王设宴招待重耳，两人饮洒叙话，气氛十分融洽。忽然楚王问重耳：“你若有一天回晋国当上国君，该怎么报答我呢？”重耳略一思索说：“美女待从、珍宝丝绸，大王您有的是，珍禽羽毛，象牙兽皮，更是楚地的盛产，晋国哪有什么珍奇物品献给大王呢？”楚王说：“公子过谦了。话虽然这么说，可总该对我有所表示吧？”重耳笑笑回答道：“要是托您的福。果真能回国当政的话，我愿与贵国友好。假如有一天，晋楚国之间发生战争，我一定命令军队先退避三舍（一舍等于三十里），如果还不能得到您的原谅，我再与您交战。”
　　四年后，重耳真的回到晋国当了国君，就是历史上有名的晋文公。晋国在他的治理下日益强大。
　　公元前633年，楚国和晋国的军队在作战时相遇。晋文公为了实现他许下的诺言，下令军队后退九十里，驻扎在城濮。楚军见晋军后退，以为对方害怕了，马上追击。晋军利用楚军骄傲轻敌的弱点，集中兵力，大破楚军，取得了城濮之战的胜利。
　　故事出自《左传·僖公二十二年》。成语“退避三舍”比喻不与人相争或主动让步。