The explanation is as follows:
"History of Han, Art and Literature" said: "Confucius took Zhou poems purely, collected Yin on the top and collected Lu on the bottom, totaling 350 articles." Obviously, the "Zhou poetry" mentioned by Ban Gu here should not be understood as a general reference to Zhou poetry, but as a collection of poems compiled. Historical Records of Confucius' Family says: "When Confucius was born, the Zhou room was small, the rites and music were deserted, and there was a lack of poetry books." It can be seen that the poems of the Zhou Dynasty were seriously lost by the time of Confucius, so it cannot be said that they were well preserved. Therefore, "Zhou Shibei" can only be understood as the existence of a book, which is an anthology of Zhou Poetry. At the same time, regarding Ban Gu's saying that "Confucius took Zhou poems purely", Wei Yuan's On Ancient Poems and Confucius' Positive Music said: "Those who took them purely obviously didn't take them. "In the book" Rural Rites ",it is said:" Two counts as purity ",and Zheng Xuan notes:" Purity is everything. " So Wei Yuan's explanation here is correct. Accordingly, the Zhou poems mentioned by Ban Gu here are even less likely to be the collective name of Zhou poems. Otherwise, The Poem of Zhou, which was taken by Confucius, became the Complete Works of Zhou Poetry. In this way, how will the next "taking Lu" be explained? Therefore, what Ban Gu said in the Annals of Literature and Art should only be understood as that before Confucius compiled The Book of Songs, Zhou Shi was popular in the world as an anthology of Zhou poems, but there were no poems of Yin and Lu in this anthology of Zhou poems. When Confucius compiled poems, on the one hand, all his works were included. On the other hand, judging from what Ban Gu said in the Book of Rites and Music in Han Dynasty, it is obvious that Confucius can only think that he compiled poems and chose poems among them. As for Confucius' "taking Lu from below", Ban Gu said in the Preface to Two Cities collected in Selected Works: "Therefore, singing Song and thinking about Sanglu were collected from Confucius and listed in the Book of Songs." Therefore, when Ban Gu quoted Confucius' right choice in compiling poems, he said that Confucius "took Lu from the bottom up".