What do you mean by Du Fu's "the grass in the north is like jade, and the green branches in Qin Sang"?

These two poems are from Li Bai's Spring Thoughts in the Tang Dynasty, not written by Du Fu! The whole poem is:

The grass is as green as Beth, and the mulberry leaves in Qin area are green.

When you miss your hometown, you were missed and sad a long time ago.

Spring breeze, since I dare not know you, why should I separate the silk curtain beside my bed? ?

The usage of the poem "The grass in your north is as blue as jade, and there are green branches in Qin Sang" is a pun. One is the spring of nature, and the other is the love between men and women. In ancient times, every time a boudoir woman was in beautiful spring, what she thought was naturally her husband who was away from home.

Yan Di: It is the northern part of Shanxi and Hebei today.

Qindi: refers to the Guanzhong area in Shaanxi Province. The two places are far apart, so it is impossible for one person to see these two different spring scenery at the same time. With a little thought, it is not difficult to understand that the woman who is full of "spring" in the poem must be in the spring of Qin, and the person she thinks of is of course in Yanbei, where the spring is still cold. It's cold outside the Yanbei Great Wall. When the spring grass finally grows green buds as thin as hair, the homesick women who are far away in Qin are already in the mulberry forest with drooping branches.

Sifu lived in the middle of Qin Dynasty. What she saw in front of her eyes was the lush mulberry forest, but what she thought of was the grass that had just sprouted in the chilly spring of Beiyan. In fact, she has no mind to appreciate the spring scenery around her, because she has been aroused by the spring scenery and remembered her husband who has been working in Yan for a long time. The implication of "Xing" in this poem is actually hidden.

Literally, that is to say, due to the different climate, the spring in Qin and Yanbei is very different in time. Another meaning of "spring" refers to the love between men and women, which is the meaning of "spring is full" that often appears in ancient poems. Then, when Yanbei's husband began to feel that he had been away from home for too long and just wanted to go home, his wife at home had been snapping her fingers all day.