This sentence came from Zuo Zongtang's " Practice on this matter ". The original text was " Worry about the world without half an acre of land; Read through ten thousand volumes and make friends with the ancients." This sentence expressed Zuo Zongtang's concern and concern for the common people in the world. He thought that he did not have enough land, but he had a heart that was worried about the country and the people. He wanted to improve his quality and knowledge through reading and learning, communicate with outstanding ancients, and make his own contribution to the prosperity and stability of the country. This sentence is often used to describe those who care about the fate of the country and the people. They devote all their energy to their own fields and constantly study and improve in order to realize their own value in life.