There is a different way to learn books. What does it mean to look at the pen through the blade?

Qi Gong, a calligrapher, has a poetic theory of learning Wei Bei's method: "The Longmen inscription is magnificent, especially the beginning. Another way to learn books is to look at the nib through the blade. " I think the last two sentences can be used in the study of liberal arts. Many students think that learning liberal arts is endorsement, but after a period of time, it will have no effect, and they may begin to hate themselves for not being smart enough. In fact, we should find the internal relationship between knowledge, from chapter to chapter, from part to whole, and grasp the part from the whole.