What was this idiom originally used to describe?

This idiom was originally used to describe the power of calligraphy, but now it is used to describe profound opinions on articles.

Idiom origin:

In the Tang Dynasty, Zhang Huaiguan wrote a book about Wang Xizhi: "When the Jin Emperor offered sacrifices to the northern suburbs, he wished the edition to be better, tailored and incisive."

Commentary: During the Jin Dynasty, the imperial court held a sacrificial ceremony in the northern suburbs. When replacing the bamboo board, the worker cut off his words and infiltrated the board for three points.

Celebrity stories:

Wang Xizhi was born in Langya (now Linyi, Shandong) in Jin Dynasty. He is one of the most famous calligraphers in the history of China. Because he was a general of the right army, later generations called him Wang Youjun. He learned from others and created a unique calligraphy style, which was called "the sage of books" by later generations.

Although Wang Xizhi's handwriting is so good, it has something to do with his talent, but the most important thing is his hard work. In order to practice his handwriting well, whether he is resting or walking, he must think about the structure of the font, try to figure out the shelf and momentum of the word, and keep paddling his fingers on his skirt. So after a long time, even my clothes were cut.

He used to practice calligraphy by the pond, and every time he finished writing, he washed his pen and inkstone in the pond. After a long time, the water in the whole pond turned black. It can be seen that he has made great efforts in practicing calligraphy.

It is said that he loves geese very much and often watches them swim around in the river in a daze. Later, he realized the principle of brush strokes from the movements of geese, which was of great help to his calligraphy skills.

Once, he went to a Taoist temple to play, and when he saw a group of geese were lovely, he asked the Taoist priest to sell them to him. The Taoist priest in Guanli admired his calligraphy for a long time and asked him to write a Huang Tingjing in exchange. Wang Xizhi liked those geese very much and agreed. So Wang Xizhi wrote a poem "Huang Ting Jing" for the Taoist temple, and the Taoist priest gave him all those geese.

On another occasion, the emperor went to the northern suburbs to offer sacrifices, and asked Wang Xizhi to write his congratulatory message on a board, and then sent workers to carve it. The sculptor was very surprised when he carved. Wang Xizhi's calligraphy and brushwork actually penetrated into the wood for more than three points. He praised: "The words of the general of the right army are really incisive!"