First, if there is no traffic jam, it will not stop.

It's from The Original Road by Tang Hanyu. Metaphor means that if you don't get rid of the wrong things, you can't build new things.

second, everything sounds when it is not flat.

it's from Tang Han Yu's preface to seeing off Meng Dongye. Generally speaking, once things are treated unfairly, they will make a voice of dissatisfaction.

third, diligent study is successful, but not diligent study is empty.

from Tang Han Yu. You have to work hard to succeed in reading. If you don't work hard, there will be no knowledge in your mind.

fourth, obstacles run across the river, and the tide turns to the east.

It's from Tang Hanyu's "A Solution to Learning". Stop the rivers flowing eastward to the sea. Although the arrogant rivers have overflowed, we still need to work hard to save them. This sentence means that at that time, the worship of Buddhism and Taoism was rampant and needed to be recovered to make it belong to the right path of Confucianism.

Han Yu (768-December 25th, 824) was born in Heyang, Henan Province (now Mengzhou, Henan Province). When he said that he practiced martial arts in Huaizhou (now Henan Province), he called himself "County King Changli" and was known as "Han Changli" and "Mr. Changli". Officials in the mid-Tang Dynasty, writers, thinkers, philosophers, politicians and educators.