Which poem is a good calligrapher in ancient and modern times?

From Shu Shu by Li Yu.

Li Yu of the Southern Tang Dynasty said that all those who were good at calligraphy were incorporated into the right army. He is talking about those who are good at calligraphy, and what they get is only an essence of Wang Xizhi, a calligrapher in the Eastern Jin Dynasty. He has a few words, a name of Lian Zhai, and is called a book saint.