"Bi Xing" is a concept with rich meanings and many ambiguities. Mao Heng's so-called "Xing" in the Western Han Dynasty includes two situations. One meaning refers to the function of "origin". Mao Shi explains that "Xing" and "Xing" are the functions of material passion, which are not necessarily related to content, but sometimes only related to phonology. It refers to a complicated and obscure metaphor. Zhu said in Biography of Poetry, "Compared with others, you can compare with this thing" and "If you are interested, you can talk about other things first to arouse the words you are reciting." It simply and accurately explains the meaning of Bi Xing. "Bi" refers to the introduction of figurative objects through analogy association or anyway association, and "writing something adds meaning". "Xing" refers to "passion for touching things", and "other things" is the scenery described in the poem, which must contain the poet's feelings of touching things. "Xing" is a more subtle and euphemistic expression than "Bi". Generally speaking, comparison is a metaphor, a metaphor for people or things, which makes its characteristics more distinct and prominent.
Metaphor is widely used in China's poetry creation. It is not only rich in form, flexible and changeable, which is convenient for poets to express their feelings, but also adds a subtle and euphemistic aesthetic feeling to the work itself, which not only greatly strengthens the image of the work, but also enriches its meaning, making it enduring and thought-provoking.
Among them, figurative expressions are widely used in The Book of Songs, the earliest collection of poems in China. This is also the earliest figurative expression. It is the application of this technique that makes these poems obtain good artistic effects and constitute the unique charm of China's classical poems.