From which ancient poem does "the face is like lotus water, and the waist is like a weak willow to help the wind" come from?

Source: Face like hibiscus and chest like jade. -Bai Juyi's Shang Yang White-haired Man

About the author: Bai Juyi (772 ~ 846) was a poet in the Tang Dynasty. The word Lotte,No. Xiangshan lay. Xinzheng, Henan, was born in Taiyuan (now Shanxi) and later moved to Xiatuo (now northeast Weinan, Shaanxi). Zhenyuan Jinshi, awarded the secretary provincial school book lang. During the Yuanhe period, Zuo Yi was a posthumous child and Zuo Zanshan was a doctor. Later, due to the above requirements, the murderer who stabbed Prime Minister Wu was severely arrested, offended powerful people and was demoted to Jiangzhou Sima. In the early years of Changqing, he was appointed as the secretariat of Hangzhou, and Bao Li was appointed as the secretariat of Suzhou in the early years, and later served as the minister of punishments. In literature, he advocated that "articles should be written in time, and songs and poems should be written for things", and he was an advocate of the New Yuefu Movement.

Appreciation: This is the seventh of 50 poems in Bai Juyi's New Yuefu, and it is a famous political allegory poem. Under the title of the poem, the author notes: "I am dissatisfied." In ancient times, an adult woman without a husband was called a dissatisfied wife, and an adult man without a wife was called a rich husband. Here, "resentment and contempt" go hand in hand, but in fact it is only resentment, referring to the poor woman imprisoned in the court. The poem does not list the experiences of the so-called "harem people" in general, but chooses a maid-in-waiting imprisoned for life as a typical example. She doesn't write about her youth and middle age, but about her old age, her hope and her despair. Through the tragic experience of this old maid-in-waiting's life, the tragic fate of the so-called "there are concubines in the palace, and 3,000 rare beauties" is vividly and comprehensively displayed, and the criminal acts of the feudal supreme ruler to harm innocent women are exposed.

Allusion: Concubine system is a great evil in feudal society. In order to satisfy their lust, feudal emperors forced their voters to be feminine and claustrophobic, depriving and destroying their youth and happiness. In March of the fourth year of Yuanhe (809), Bai Juyi pointed out in the performance "Please pick my wife in the palace" presented to the emperor (that is, please pick some maids): "The palace people taught each other for a long time. Besides worrying about driving, there are a lot of them.