During the Spring and Autumn period, after Chu defeated Song, General Zi Zhong claimed credit and demanded two northern territories from King Zhuang of Chu as a reward. The king was about to agree, but Minister Shen Gong Wuchen strongly objected, arguing that granting those lands would invite invasion from Jin and Zheng. Consequently, the king refused. Zi Zhong, burning with resentment, swore vengeance against Wuchen.
Another Chu minister, Zifan, also desired the beautiful Xia Ji. The official Wuchen warned, 'Xia Ji's fate is inauspicious—you must not marry her.' Yet later, Wuchen himself married Xia Ji and fled with her to the state of Jin. This betrayal left Zifan burning with hatred for Wuchen.
After King Zhuang of Chu died, King Gong of Chu ascended the throne. By then, Wu Chen had become a high minister in the state of Jin. To settle old scores, Zi Zhong and Zi Fan joined forces, slaughtered Wu Chen's entire family, and divided up their property and concubines. When Wu Chen learned of this, he was furious and vowed revenge. He sent a letter to Zi Zhong and Zi Fan, which read: "You two have acted with such cruelty, forcing innocent people to suffer. I swear that I will make you both weary and worn out from constant travel and battle." And indeed, Wu Chen later used his influence in Jin to repeatedly provoke conflicts between Chu and its neighbors, ensuring that Zi Zhong and Zi Fan were forever dispatched on exhausting military campaigns, never able to rest in peace.
"You two villains harbor evil intentions, slandering the ruler with insatiable greed, killing so many innocent people—truly detestable. I will make you run about busily until you drop dead from exhaustion!"
To fulfill his promise, Wu Chen brought chariots and soldiers to the backward state of Wu, training Wu's troops in chariot driving and archery. He stirred up resentment against Chu's control, urging the Wu king to constantly raid Chu's borders.
Under Wu Chen's meticulous training, the Wu army grew increasingly powerful, launching repeated campaigns to conquer Chu's eastern vassal states one by one and annex them into Wu's territory, steadily expanding their strength. As a result, urgent dispatches constantly flooded into Chu's capital, and whenever King Chu received a military alert, he would dispatch Zi Zhong and Zi Fan to lead reinforcements.
Due to relentless Wu attacks on Chu and its vassal states, Zi Zhong and Zi Fan barely rested after one campaign before being ordered out again. In a single year, they led their armies back and forth seven times, utterly exhausted. Wu Chen had finally achieved his revenge.
Later, the idiom "burdened with running" came to describe being exhausted from constant rushing, or being overwhelmed by numerous tasks.
Source: *Zuo Zhuan*, "Duke Cheng, Seventh Year"
Meaning of the Idiom: Later, the Chinese idiom "疲于奔命" came to describe being exhausted from constant rushing, or being overwhelmed by numerous tasks.