"Preface to Mao Poetry" said: "The North Wind" is also a curse. Defending the country and defending the country is not for bullying, and the people are not close. "Judging from the" same car "in the poem, the people generally refer to the ordinary aristocrats at that time. Fang Yurun thinks it was written by sages who predicted the crisis (The Original Book of Songs), and Wang Xianqian thinks it is "the words of sages who meet each other and avoid the land" (The Collection of Three Poets' Righteousness). In fact, the poem mentioned in the Preface to Poetry is correct, and it should be a poem reflecting the escape of nobles.