This poem was written in 744 AD (Tianbao three years), and Li Bai was in Chang 'an. Why emphasize this point? Because when Li Bai went to Chang 'an, the Tang Dynasty was in its heyday, but the An-Shi Rebellion broke out in 755 AD. The Anshi Rebellion was not only a turning point in the Tang Dynasty, but also a great turning point in China's whole Tang poetry. Li Bai has already felt it in Chang 'an, so that under the background of his frustration, there is an eternal story of "Until I raise my cup, I ask the bright moon to bring my shadow and let us three". He is full of the ideal of making contributions, but the court only regards him as a funny poet. In the prosperous Tang dynasty, people had the integrity of bleeding and sacrificing in the frontier. You can imagine how depressed Li Bai is. Ideal is a soaring Dapeng, while reality is a caged bird. Li Bai, standing on the court full of courtiers, deeply felt that most people were extremely similar, inferior and flattering. He is lonely, and he feels that only the high moon and his own shadow deserve to be with him, to be a real person and to drink with him. He is Li Bai, so he can't keep a low profile. Even if it is a period of time, it will be lonely and imposing. He was obviously drinking alone under the tree, but he insisted that he was until, holding up my cup, I asked the moon to bring me my shadow and let the three of us. Li Bai's depressed and free-spirited is not only the characteristic of Li Bai, but also the characteristic of poets in the prosperous Tang Dynasty. They are completely different from the poets in the Song Dynasty, so it is not easy to find a particularly lonely and depressed sentence in Li Bai. Only the depression behind this free and easy, a kind of depression implied in chic.