Do you know the story of Ning Guan cutting a mat?

There is an idiom in Chinese called "Guan Ning gives up his seat". Although literally only one person's name is mentioned, in fact, this story involves two protagonists, one is Guan Ning and the other is Hua Xin.

It is said that Guan Ning and Hua Xin grew up together. They are both buddies and classmates in private schools. They usually play, work and study together. One day, two people were hoeing and growing vegetables together in the garden (often guessing that this might be a labor class assignment arranged by the teacher or parents). When they saw a piece of gold on the ground, Guan Ning turned a blind eye, treated it as no different from a tile stone, and continued to work with a hoe. Huaxin picked up the gold, threw it away and went on working.

On another occasion, they sat on the same mat on the ground to study (in the Han Dynasty, sitting on the floor was more popular than sitting on a stool). At this time, an official happened to pass by the door in a beautifully decorated carriage. Ning Guan still sat in the same place and continued to concentrate on his studies, while Huaxin put down his book and left his seat. He ran out and looked at it for a while before coming back. So Guan Ning cut off the mat with a knife in a rage, sat apart from Hua Xin and said, "You are no longer mine.

The book Shi Shuo Xin Yu is as follows:

Guan Ning, Huaxin Garden hoes vegetables. Seeing a piece of gold in the field, there was no difference between a hoe and a tile stone. China caught it and threw it away. I have also tasted the taste of reading at the same table. Those who pass by the entrance of the porch would rather study as before and read those useless books. Ning cut his seat and sat down separately, saying, "My son is not my friend."