During the Warring States period, the states of Wei and Zhao signed a peace treaty, and the King of Wei sent his son to the Zhao capital, Handan, as a hostage.
Before leaving, the King of Wei selected his trusted minister Pang Cong to accompany and care for his son.
Pang Cong knew that some ministers at court held objections against him, and he worried that after leaving the State of Wei, someone would speak ill of him before the King of Wei. He subtly asked the king, "Your Majesty, if someone reported to you that a tiger had appeared on the main street of our capital, Daliang, would you believe it?"
"Of course I wouldn't believe it—how could a tiger wander into the marketplace?" King Wei of Wei answered without a second thought. Pang Cong pressed on, "What if a second person immediately reported the same thing—that a tiger had appeared on the main street? Would you still doubt it?" The king considered this and replied, "If two people said so, I might begin to waver." "And if a third person came to report the same news," Pang Cong persisted, "would you believe it then?" King Wei admitted, "If three people all said the same thing, I would be fully convinced."
"Your Majesty!" Pang Cong said. "It's obviously impossible for a tiger to run into the main street, but because three people reported it to you in succession, you believed it was true. Now I am accompanying the crown prince to Handan, which is much farther from Daliang than the palace is from the main street, and there will certainly be more than three people speaking ill of me behind my back. I hope Your Majesty will look into this carefully."
King Wei suddenly understood and nodded, saying, "I see. Go with peace of mind!"
Pang Cong bid farewell to King Wei and accompanied the crown prince to Handan. After his departure, ministers who resented him began slandering him before the king. At first, King Wei dismissed their words, but as more voices joined the chorus, doubt crept in. Over time, he gradually came to believe the falsehoods.
When the prince's term as a hostage ended and Pang Cong returned with him to the Wei court, King Hui of Wei no longer entrusted Pang Cong with important duties—his earlier fears had become reality.
Later, people used the idiom "Three People Make a Tiger" to describe how repeated rumors or falsehoods can make people believe them as true.
Source: *Strategies of the Warring States*, Chapter "Strategy of Wei II"
Meaning of the Idiom: Later, the Chinese idiom "三人成虎" came to describe how repeated rumors or falsehoods can make people believe them as true.