The word "six books" comes from Zhou Li: "Bao Zhang remonstrates the evil of the king, while raising the son of the country with Tao is to teach six arts: one says five rites; Second, six music; Three shots and five shots; Four days and five days; Five words and six books; Six says nine; " . However, Zhou Li only described the term "Six Books", but did not explain it.

Xu Shen, a scholar of the Eastern Han Dynasty in China, wrote in Shuo Wen Jie Zi: "Li Zhou entered primary school at the age of eight, and there were only six books. One pointed at something and said: People who point at things can see and know, and they can see by observing, so can' up' and' down'. Second, pictographic characters: pictographic characters, painted as objects, follow the body, as do' day' and' month'. Third, form and sound: form and sound, in the name of things, complement each other with examples,' Jiang' and' River' are also.

Fourth, knowing and doing: people who know and do are friendlier than others, and let them see the meaning,' martial arts' and' faith'. Fifth, turn notes: the person who turns notes builds a song and agrees to accept it. The same is true of' Kao' and' Lao'. 6. Borrowing: Borrowers have nothing to say, and they all rely on their voices to make excuses, as do' preface' and' long'. Xu Shen's explanation is the first official record of the definition of six books in history. Xu Shen is still the core of the interpretation of the Six Books in later generations.