In the Northern Song Dynasty, there was a Chen Sheren in Bianjing who happened to get an old edition of Du Fu's poems. He was a treasure. However, due to the poor preservation of this book, the words in many poems have fallen off. Once, when Mr. Chen read Poems to Send a Captain Cai, he found that there was a word missing after the word "bird" in the sentence "one bird is light, one gun is urgent for thousands of people to call". After careful consideration, he couldn't tell what it was.
One day, when he was talking about poetry with some poetry friends, he raised this question, hoping that everyone could make up the most appropriate word. Someone wrote the word "disease", which is considered to be the best expression of Cai's quick and brisk vertical jump. Some people think it is not good, because the pronunciation and meaning of the word "disease" in the previous sentence and the word "urgency" in the next sentence are too close, which seems a bit repetitive. Others wrote the word "degree", but Chen Sheren thought that the word "degree" was too blunt to show the characteristics of being as light as a bird. Some people even suggested using the words "health", "promotion" and "health", but everyone was not satisfied.
Later, Mr. Chen found a relatively complete collection of Du Fu's poems elsewhere and turned to Poems to Send Cai. The original sentence was "A bird is lighter". The word "Guo" was used to describe Captain Cai's jumping high and fast, like a bird flying around in front of his eyes, which was really appropriate.