Liu Che, Emperor Wu of the Han Dynasty, was very happy when he heard that General Li Ling led the army into the Xiongnu border. Many ministers congratulated the emperor on his cleverness and good use of people. Later, Li Ling was defeated and surrendered, and Emperor Wu was very angry. The minister who congratulated him in turn accused Li Ling of being useless and disloyal. Seeing Sima Qian standing by without saying a word, Emperor Wu of the Han Dynasty asked him what he thought of the matter.

Sima Qian said, "Li Ling has only 5,000 infantry, which goes deep into the enemy's hinterland and is surrounded by 80,000 tarquin. But he fought for more than ten days and killed more than 10 thousand enemies, which is already a great achievement. Finally, he ran out of ammunition and cut off his retreat before he stopped fighting. Li Ling didn't really surrender. He must also want to repay your majesty by paying his debts. His credit can make up for his mistakes. "

When Emperor Wu of the Han Dynasty heard that Sima Qian defended Li Ling, he deliberately belittled Li Guangli and was furious. He put Sima Qian in prison. Soon, there were rumors that Li Ling led Xiongnu soldiers to attack the Han Dynasty. Emperor Wu of the Han Dynasty believed it and was so anxious that he killed Li Ling's mother, wife and children. Sima Qian was also sentenced to death for this incident. In order to cater to the emperor, the Ting and Zhou Dynasties imposed the most cruel "castration" on Sima Qian.

Sima Qian suffered all kinds of devastation and wanted to commit suicide after being tortured. But on second thought, the death of a humble man like him, in the eyes of many rich and powerful people, is like "nine cows are dead", which will make people laugh, not get sympathy. So he is determined to bear the burden of humiliation and spend his whole life writing historical records.

In Sima Qian's time, a dead man with no identity was worse than a dog at the end of the road, so he bravely survived and finally finished this great historical work "Historical Records". Sima Qian wrote a letter to his good friend Ren, in which he talked about this ideological change. Later generations extended "nine cows die a hair" to the idiom "nine hairs" in their letters, which is used to describe that most things are only a part of them, such as a hair of nine cows.