Jia Dao of the Tang Dynasty was a famous poet of the Kuyin School. What is the Kuyin Sect? Just for a line of poetry or a word in a poem, you will not hesitate to expend your efforts and efforts. Jia Dao spent several years writing a poem. After the poem was completed, he burst into tears. He was not only happy, but also felt sorry for himself. Of course, he doesn't have to work so hard every time he writes a song. If that were the case, he wouldn't be able to become a poet.

Once, Jia Dao rode a donkey into the official road. He was pondering over a poem called "Inscribed on Li Ning's Residence in Seclusion". The full poem is as follows:

Living leisurely with few neighbors,

The grass path leads into the deserted garden.

The bird stayed in the tree beside the pond,

The monk knocked on the door under the moon.

Crossing the bridge divides the wild colors,

Moving rocks moves cloud roots.

I have been away for a while and come here again,

You live up to your promise.

But there was one thing he was undecided about, that is, he felt that the "push" in the second sentence of "The bird stayed in the tree beside the pond, and the monk pushed the door under the moon" should be replaced by "knock". But he also felt that "knocking" was a bit inappropriate, and it would be better to "push". I don't know whether it is better to "knock" or "push". The hand made a "push" gesture while making a "knocking" gesture, thinking over and over again. Unknowingly, he rode a donkey into the third quarter of the honor guard of the high official Han Yu (one of the eight great masters of the Tang and Song Dynasties).

Han Yu asked Jia Dao why he broke into his honor guard. Jia Dao read the poem he had written to Han Yu, but he couldn't decide whether to use "push" or "knock" in one of the lines. Han Yu listened and said to Jia Dao: "I think it's better to use 'knock'. Even in the dead of night, when visiting friends, knocking on the door means you are a polite person! Moreover, the word "knock" made the night more quiet, and there was a little more noise. Besides, it reads louder." Jia Dao nodded in praise after hearing this. The two rode their horses side by side back to Han Yu's home, and later they became very good friends.

Thinking about it ever since It has become a popular and commonly used word, used to describe thinking over and over again when writing an article or doing something.