The theory of offering poems: an ancient view on the origin of works in the Book of Songs. Together with "Wang Guan's Collection of Poems" and "Confucius' Deletion of Poems", it is considered to be the source of the compilation and collection of "The Book of Songs". At that time, the emperor ordered the princes to submit poems in order to "test the beauty and evil of the customs". According to records from pre-Qin and other ancient books such as Guoyu and Zuozhuan, the Book of Songs mainly comes from poems presented by public ministers, who used poems to satirize or praise. It is now generally believed that many poems in "Daya", "Xiaoya" and "Guofeng" in "The Book of Songs" may have been collected through poetry presentation.