The meaning of this two-part allegorical saying is: to describe the great brushwork of calligraphy. Nowadays, the problem of metaphor analysis is very profound.
Idiom: Go straight to the point.
Interpretation: According to legend, Wang Xizhi wrote on the wooden board, and when the carpenter carved it, he found that three points of the handwriting penetrated into the wooden board (three points equals 1 cm). Describe that calligraphy is very powerful. Nowadays, the problem of metaphor analysis is very profound.
Source: Zhang Huaiguan's Broken Wang Xizhi in the Tang Dynasty: "When the Jin Emperor offered sacrifices to the northern suburbs, I wish the edition a better one, and I wish it a better one." Poetry: writing people and ghosts is superior, stabbing greed and stabbing abuse. -Guo Moruo's evaluation of Strange Tales from a Lonely Studio