This story comes from Lu Chunqiu Lu Xun. There are also records in Zuo Zhuan and Han Feizi, but they are not as complete as Lv Chunqiu. Danger, regardless of the enemy, not listening to advice, greedy for small profits, agreed to borrow. In fact, it helped the State of Jin to destroy the State of Guo, and the result was the same fate. This is a profound historical lesson.

meaning

The idiom "cold lips and cold teeth" comes from the story of "cold lips and cold teeth". Metaphors are closely related and have the same interests. The idiom "lips and teeth depend on each other" is transformed from the story of "auxiliary car depends on each other", which means that they are closely related and interdependent. These two idioms are mostly used to describe the relationship between two neighboring countries. Some people directly regard "auxiliary vehicles depend on each other" as an idiom, which means mutual cooperation and interdependence. Without your lips, your teeth will feel cold. Used to describe the close relationship and related interests between the two sides. If one side is hit, the other side will fidget. This idiom story comes from Zuo Zhuan's Five Years of Xi Gong: "As the saying goes, the so-called' auxiliary cars depend on each other, and the lips are dead and the teeth are cold' is also called embarrassment. Nowadays, people often use this word to describe the interdependent relationship between the two sides, and no one can live without anyone.