During the Spring and Autumn period, civil war erupted in the state of Jin, and Prince Yiwu fled to the state of Qin. To secure Qin's support for his claim to the throne, Yiwu promised to cede five cities to Qin once he became ruler. With Qin's help, he returned to Jin and was crowned Duke Hui of Jin, but he broke his promise and refused to hand over the cities.
Soon after, the state of Jin suffered a famine with poor harvests, and Duke Hui of Jin approached the state of Qin to negotiate the purchase of grain. Despite the duke's previous breach of trust and broken promises, Qin did not refuse his request and still granted it.
Unexpectedly, a year later, Qin also suffered a famine and sent envoys to Jin to purchase grain. Duke Hui of Jin, however, gloated and refused to agree to Qin's request. Minister Qing Zheng, recalling past events, was deeply dissatisfied with Duke Hui's actions and said indignantly:
"To turn your back on Qin's kindness and rejoice in its misfortune is immoral; to hoard your own possessions and refuse to aid others, thereby angering a neighboring state—what benefit is that to Jin? If this continues, our state will be lost—how can we still defend it?"
Duke Hui of Jin's maternal uncle, the Grand Master Guoshe, countered, "Our earlier failure to honor our promise of ceding five cities to Qin was the root cause of our broken relations. If we don't resolve that fundamental issue and only agree to sell them grain, it's like having hair without skin. Now that the skin is gone, where can the hair attach? Since matters have come to this, we might as well refuse to sell them any grain at all!"
Qing Zheng opposed Guo She's view and continued, "If we abandon trust and betray our neighbor, who will come to our aid when disaster strikes? Losing help leads to ruin. That is exactly our situation now."
Guo She insisted on his view, saying, "Even if we give Qin grain now, it won't reduce their resentment toward us; instead, it will strengthen them by solving their difficulties. My opinion is still not to sell them grain!"
Duke Hui of Jin followed the advice of his minister Guo She, rejecting Qing Zheng's counsel to sell grain to the state of Qin. Qing Zheng sighed, warning that the duke would regret this decision. And indeed, the following year, war broke out between Qin and Jin. Duke Hui was defeated in battle and taken prisoner by the Qin forces.
Later, the idiom "If the skin is gone, where will the hair attach?" came to describe that when the foundation is lost, everything dependent on it cannot survive.
Source: *Zuo Zhuan*, Chapter "Duke Xi's Fourteenth Year"
Meaning of the Idiom: Later, the Chinese idiom "皮之不存，毛将焉附" came to describe when the foundation is lost, everything dependent on it cannot survive.