Duke Ling of Jin, known for his brutal temper, once had a chef executed on the spot for undercooking bear paws. Two palace attendants were ordered to stuff the body into a basket and carry it out for burial.
As it happened, the corpse was discovered by two upright ministers, Zhao Dun and Shi Ji. After learning what had happened, they were furious and decided to enter the palace to remonstrate with Duke Ling of Jin. Shi Ji went first to seek an audience, but the duke, sensing from his expression that he had come about the cook's murder, pretended not to see him. Only after Shi Ji had advanced three times and reached the eaves did Duke Ling glance at him and say dismissively, "I already know my mistake and will correct it from now on."
Shi Ji, hearing this, responded gently, "Except for sages and worthies, who is without fault? To correct a mistake once made is the best course. If you can accept your ministers' wise remonstrances, you will be a good ruler."
However, Duke Ling of Jin never truly recognized his own faults and continued his brutal behavior. Prime Minister Zhao Dun repeatedly admonished him, but the Duke not only ignored the advice but grew so resentful that he sent an assassin to murder Zhao Dun. Unexpectedly, the assassin refused to harm the upright and loyal Zhao Dun, choosing suicide instead. When this plot failed, Duke Ling changed tactics, pretending to invite Zhao Dun to a palace banquet, planning to kill him during the feast. Zhao Dun was rescued by his guards, foiling the Duke's scheme once more. In the end, this wicked ruler was killed by a man named Zhao Chuan.
Later, the idiom "To err is human" came to describe that ordinary people, not just sages or worthies, are all capable of making mistakes.
Source: *Zuo Zhuan*, "Duke Xuan, Year 2"
Meaning of the Idiom: Later, the Chinese idiom "人非圣贤，孰能无过" came to describe ordinary people, not just sages or worthies, are all capable of making mistakes.