Explanation: It is a metaphor for the richness of books or the depth of book addiction.

Origin: Li Mi of the Northern Wei Dynasty read widely, but he didn't intend to be an official, so he spent all his fortune on books. He has carefully reviewed as many as 4000 books. He has a famous saying: "If the husband has thousands of books, why not leave a hundred cities in the south!" In other words, as long as there are thousands of books, there is no need for officials to run 100 cities.

There are as many words in the metaphor book:

1, vast as a sea of smoke: vast as a sea. Refers to books, documents, etc. , a large number, extremely rich.

2, left picture right history: books are everywhere, metaphorically like books and eager to learn.

3, sweating: there are many description books.

4, sitting in a hundred cities: metaphor is rich in books at home.