During the Warring States Period, countries often went to war with their enemies and formed pacts with their allies. To ensure these pacts would not be broken, kings would send their own children to their allies as hostages, as proof of their commitment to the pact.

One day, Pang Cong, a Minister of the State of Wei, was to accompany the Prince of Wei to the State of Zhao as a hostage. Before setting off, Pang Cong was worried that someone would take the opportunity to harm his reputation. So, he told the King of Wei, "My King, your humble subject has a question for you.""Speak", said the King.

"My King, If someone were to tell you there was a tiger in the city would you believe him?" The King laughed and replied, "Of course not! That is impossible!" Pang Cong asked again,"If a second person also told you that there is a tiger in the city, would you believe him?" The King of Wei replied,"If that happened, I would wonder if it were true."

Pang Cong asked again,"What if a third person also told you that there is a tiger in the city, would you believe him?" The King of Wei said,"Well, if three people say the same thing, then it has got to be true!" Pang Cong said, "Even young children know that it is impossible to find a tiger in the city. But, if three people repeat the same rumor, the rumor will seem to be true." Pang Cong paused a while, and continued to speak. "The State of Zhao is far away and the journey will take a long time. I know that more than three people who will try to spread rumors about me. Therefore, I hope you will not believe these rumors, my King."

The King of Wei nodded and said, "I understand what you mean. Rest assured, I will not believe any rumors about you." However, as Pang Cong predicted, many people spread rumors about him while he was gone. Sadly, the King of Wei believed the rumors, and did not trust Pang Cong anymore.

　　戰國時代，國與國之間常常發生戰爭，也因此訂立了不少盟約，為了使大家真正能遵守盟約，通常都會把國君的子孫交給對方當作人質，代表自己真的願意遵守盟約。

　　有一次，魏國大臣龐蔥，要陪魏國王子到趙國當人質。出發前，龐蔥擔心有人會利用機會說自己的壞話，於是對魏王說：「大王，微臣有幾個問題想請問您。」「你問吧！」

　　「大王，如果現在有一個人告訴您，街上出現了一隻老虎，您相信嗎？」魏王笑著說：「怎麼可能？街上怎麼可能會出現一隻老虎？」龐蔥又問：「如果有第二個人也告訴您，街上出現了一隻老虎，大王會相信嗎？」魏王回答：「這樣的話，我會半信半疑。」

　　龐蔥繼續問：「如果有第三個人又告訴您，街上出現了一隻老虎，您會相信嗎？」魏王說：「已經有三個人這樣子講了，我當然會相信啦！」「街上不可能會有老虎，這是小孩子也知道的事，可是有三個人告訴您，好像真的有老虎了。」龐蔥停了一會兒，又接著說：「現在趙國到魏國的距離，比您到街上的遠得多；再加上會說我壞話的人，不可能只有三個。所以……希望大王別相信這些謠言。」

　　魏王點點頭說：「我知道了。你放心好了，我不會相信那些說你壞話的人。」龐蔥陪王子去趙國之後，果然有很多人跟魏王說龐蔥的壞話，魏王最後還是相信了這些謠言，不再重用龐蔥了。