What is the specific meaning of the bright moon image in ancient poetry?

Moon: the perfection of life, the regret of homesickness

"looking at the moon and thinking of one far away", "Sad for spring and autumn", "Seeing flowing water makes me think that my years are fleeting" and "Indus drizzle makes me sad and sad"

Other names of the moon: themoon, Yupan, Yingou, Chanjuan and Guigong; "Jade Plate", "Jade Wheel", "Yuhuan", "Jade Hook", "Jade Bow", "Jade Mirror", "Sky Mirror", "Mirror", "Jade Rabbit", "Chang 'e" and "Toad" Moon: In ancient Chinese poetry, it is a common brushwork to use the moon to set off feelings. Generally speaking, the moon in ancient poems is synonymous with homesickness. Li Bai's Thoughts on a Quiet Night: "so bright a gleam on the foot of my bed, could there have been a frost already?, lifting myself to look, I found that it was moonlight, sinking back again, I thought suddenly of home." This poem shows Li Bai's homesickness. The moon in the poem is no longer a purely objective image, but an image imbued with the poet's feelings. Wang Jian, a Tang Dynasty, wrote "Looking at Du Langzhong at Fifteen Nights": "Tonight, the moon is full of hope, and I don't know whose house Qiu Si will fall." The poem points out the universal human feelings on this full moon night with euphemistic questions, and implicitly shows the poet's deep yearning for his hometown friends.

In addition, the "moon" has the following images

( 1) The bright moon contains the sadness of people on the border.

such as: "The sand is like snow before returning to Le Feng, and the moon outside the city is like frost"; "The moon was bright in Qin dynasty and closed in Han dynasty, and the people of the Long March have not returned" is solemn and stirring.

(2) The bright moon contains emotional helplessness.

For example, Xie Zhuang said, "A beautiful woman walks in the dust, and a thousand miles away, the moon is shining." Prayers and blessings; Zhang Jiuling "the moon, grown full now over the sea, Tianya * * * at this time." Hope and longing.

(3) The bright moon implies the eternity of time and space.

"In ancient times, if people are running like water today, they can look at the bright moon." The looting of life by time and the helplessness of life in front of time are vividly demonstrated.