During the Tang Dynasty, a man named Jia Dao (born in the year 779), a well-studied scholar and poet, went to the capital to take the imperial examination.

One day as he rides a donkey through the city streets, a poem begins to form in his mind. A portion of the poem comes into his head like this:

“The bird sits on the tree branch near a pond,
A monk approaches and knocks at the gate...”

At the same time, he wondered if the word “push” would be better than “knock” in his poem.

As he rides down the street, he imagines the monk pushing or knocking. Soon he finds himself making motions of pushing and shaking a fist in a knocking motion as he debates which word to use. He is quite a sight as he makes his way down the street on his donkey with hands and fists flying about as the internal debate continues.

As he amuses people along the street, he becomes completely lost in his thoughts and does not see the mayor's procession coming in the opposite direction. Jia Bao is blocking the way for the procession to continue down the road, and the mayor's guards immediately decide to remove Jia Bao by force. Jia Bao, not realizing that he was in the way, apologizes, explains his poetic dilemma and awaits his punishment for blocking the mayor's way.

The mayor, Han Yu, a scholar and author of prose himself, finds himself intrigued by Jia Dao's poem and problem. Han Yu gets off his horse and addresses Jia Bao, stating, “I think knock is better.” The relieved Jia Bao raises his head and is invited by the mayor to join the procession, and are seen riding off together down the street, exchanging their ideas and love of poetry.

In modern Chinese, this 反復推敲 idiom is used when someone is trying to decide which word to use in their writing or when struggling to decide between two things when neither seems to have a downside.