From the full text:
Bai Ye's poems are incomparable, and his thoughts are unparalleled.
The fresh Yu opened his mansion, and the handsome Bao joined the army.
Spring trees in Weibei, dusk clouds in Jiangdong.
When a bottle of wine, important and detailed essays.
——Du Fu's "Recalling Li Bai in Spring"
This is a metaphor for Yu Xin and Bao Zhao. It is mainly because Du Fu highly praised Li Bai's poems like Yu Xin's. Fresh, as handsome as Bao Zhao.
Yu Xin and Bao Zhao were both famous poets in the Southern and Northern Dynasties. Yu Xin served as an official in the Northern Zhou Dynasty to the general of Hushi, and Kaifu Yi shared three divisions, namely Sima, Situ, and Sikong. He was known as Yu Kaifu in the world. During the Liu and Song Dynasties, Bao Zhao served as a member of the Jingzhou Former Army and was known as Bao Canjun in the world.
Comparing Li Bai with Yu Xin and Bao Zhao shows that Li Bai's poems have their own characteristics - freshness and elegance, which together constitute the style of Li Bai's poems. This not only corresponds to "poetry is invincible" and "thinking is unparalleled", but also shows the poet Du Fu's praise of Li Bai.