When the State of Chu rallied several smaller states to attack the State of Song, Song remembered it had once helped Chong'er, a prince of Jin who later returned to his homeland and became its ruler, known as Duke Wen of Jin. In desperation, Song sent an urgent plea to Duke Wen for aid.
Xian Zhen, assistant commander of the Jin army's lower division, said to Duke Wen of Jin, "Repaying kindness and achieving hegemony—this one move decides it all. The opportunity must not be lost." Duke Wen deeply agreed.
The new ruler of Jin had just ascended the throne, and the kingdom's military strength was insufficient, while the King of Chu, backed by the armies of Chen, Cai, Cao, and Wei, was an unstoppable force.
Duke Wen of Jin sought advice from his uncle Hu Yan (also known as Jiu Fan), saying, "The state of Song must be rescued, and I will go to war against Chu, but they outnumber us—what should I do?" Hu Yan replied, "In matters of ritual, loyalty and trust are the foundation; on the battlefield, deception and cunning are the best strategy. To defeat Chu, we must use trickery." The Duke then privately summoned Yong Ji and asked, "Someone advises me to use deception to overcome the mighty Chu—what do you think?"
Yong Ji said, "Burning down the entire forest to hunt may yield a large catch, but afterward there will be no beasts left to hunt; teaching soldiers to win through deception may bring victory, but afterward there will be no honest people left in the state."
After careful deliberation, Duke Wen of Jin appointed Hu Yan as the commander of the upper army to lead the expedition to rescue the Song state.
Fox Yan devised a plan: "Our army need not clash with Chu's forces. First attack Chu's allies Cao and Wei, who are too weak to defend themselves. The King of Chu will surely lead his troops north to rescue them, and thus the siege of Song will be lifted without doubt."
King Chu fell for the trap, and his general Ziyu led the allied forces to confront the Jin army. The Jin troops deliberately retreated ninety li before engaging the Chu forces at Chengpu. Choosing the weakest point, the Jin army first crushed the Chu right flank, composed of Chen and Cai troops. Meanwhile, the main Jin force feigned a retreat, luring the Chu left flank into pursuit. Then, with the Song and Jin armies attacking from both sides, they achieved a decisive victory at the Battle of Chengpu.
When Duke Wen of Jin rewarded his ministers for their contributions, he first raised a toast to Yong Ji before honoring Hu Yan. His advisors questioned this, saying, "Hu Yan's strategies won us the battle, yet you honor Yong Ji first—why?" Duke Wen replied, "Hu Yan's advice was like a swift horse covering a thousand li in a day—effective for the moment. But Yong Ji's counsel was like a steady hand on the reins—it ensures lasting order. A ruler must value what endures, not just what wins." This story reminds us that true wisdom lies in prioritizing long-term principles over short-term gains.
The generals asked, "At the Battle of Chengpu, it was Uncle Fan who devised the strategy and secured victory. Is it fair to reward him after others for his own plan?" Duke Wen replied, "You do not understand. Uncle Fan's plan was a temporary expedient, while Yong Ji's advice holds eternal value. A temporary measure is important, but lasting benefit is far more precious." The phrase "outnumbered by the enemy" can refer to a weaker army facing a stronger one, or more broadly, any situation where power is unevenly matched.
Source: *Han Feizi*, Chapter "Nan Yi"
Meaning of the Idiom: Later, the Chinese idiom "彼众我寡" came to describe how true wisdom lies in prioritizing long-term principles over short-term gains.