According to records, "keeping one word and nine" comes from Sima Qian's Biography of Historical Records and Ping Yuanjun. There is such a passage in the book: "When Mr. Wang arrives in Chu, Zhao is more important than Jiuding Road. Teacher Mao's golden tongue is better than a million teachers. I won't dare to go back to my face. " The main reason is that Mr. Kumaosui's three-inch golden tongue is more useful than a million-strong army, and what he said is more weighty than Jiuding.
According to records, during the Warring States Period, Handan, the capital of Zhao State, was surrounded by Qin Jun, and Ping Yuanjun was ordered to lead Mao Sui and others 19 people to Chu to reinforce.
At first, I tried my best to persuade troops to save Zhao. Later, he stood up and said something to the king of Chu.
Mao sui's words were to the effect that although Chu had many soldiers, he always lost when he started fighting. If the State of Chu does not save Zhao today, it will be isolated in the future. Even though Chu has a large number of troops, most of the battles before Chu were defeated, so there is not much chance of winning in the face of aggression. Without Zhao's help, Chu would certainly be as Enemy at the Gates as Zhao.
Hearing this, the king of Chu felt very reasonable and sent troops to save Zhao. So after Ping Yuanjun returned to China, he sent out a sigh with emotion. The general meaning of emotion is to praise Mao Sui's eloquence, and his words can be compared with Jiuding.
Later, the idiom "a promise is a promise, a promise is a promise" has continued to this day and evolved into the meaning of speaking with weight and honesty.