The Yellow Emperor was a legendary tribal leader in ancient China.
During the era of the Yellow Emperor, ancient Chinese civilization saw the invention of wooden houses, carts and boats, sericulture and weaving, and written characters. For this reason, the Chinese people honor the Yellow Emperor as their ancestor and proudly call themselves descendants of Yan and Huang.
Legend has it that the Yellow Emperor once traveled to Mount Juci. He lost his way near Xiangcheng. There, he met a boy herding horses and asked, "Child, do you know where Mount Juci is?"
"I know," the child replied. "Then do you know where a man named Dayuan lives on Juci Mountain?" the Yellow Emperor asked again. The child said, "I know that too." The Yellow Emperor, delighted, said, "Ah! You are quite remarkable. Let me ask you another question—do you know how to govern a country?"
The boy thought for a moment and replied, "Governing a country is nothing extraordinary. Years ago, while traveling the world and ill, an elder advised me: 'Travel at sunrise, rest at sunset,' to conserve energy for more journeys. The principle of governing a country is the same."
Emperor Huangdi nodded and said, "You speak well, but with so many people in the world, how can they be governed?"
The boy pointed to the herd of horses he was tending and said, "Governing the people of the world is much like tending these horses. The vast majority are docile; only a few are troublemakers. Drive out the troublemakers, and the entire herd will be at peace."
The Yellow Emperor was so impressed with the boy's answer that he bowed to him respectfully several times before taking his leave.
Later, the idiom "black sheep" came to be used as a metaphor for someone who harms the group.
Source: *Zhuangzi*, "Xu Wugui"
Meaning of the Idiom: Later, the Chinese idiom "害群之马" came to describe a metaphor for someone who harms the group.