The author's source is Tang Zhanghuai's Book Broken Wang Xizhi: "Wang Xizhi's book is a blessing edition, and the workers cut it, and the pen is incisive." Idiom allusions During the Jin Dynasty, there was a famous calligrapher named Wang Xizhi.
On one occasion, Wang Xizhi wrote on a wooden board. After he finished writing, the workers tried to erase the handwriting, and they couldn't erase it for a long time, so they had to scratch it with a knife, scratch it! I didn't expect to scrape the three-minute thick wood to clean the handwriting. It turns out that Wang Xizhi's handwriting has penetrated into the wood three-minute thick! This shows how deep Wang Xizhi's writing skills are!
Later, someone changed Wang Xizhi's writing into the idiom "penetrating into the wood" to describe a person's writing, speech or performance. Good meaning!