What's the name of this poem?

In 724 (the 12th year of Tang Kaiyuan), Li Bai visited the Three Gorges in Sichuan, met the Taoist Sima Cheng Town in Jiangling, and was appreciated by Sima Cheng Town. In the later Tang Dynasty, Emperor Xuanzong ordered Sima Cheng to establish a Taoist temple in Wuwangshan and inscribed a plaque. According to Zhang Yanyuan's Records of Famous Paintings in the Tang Dynasty, Sima Cheng Town is not only profound in Taoism, but also highly accomplished in poetry, calligraphy and painting. He once made a landscape mural in a balcony palace, which was 16 feet high and 95 feet long, in which cranes, clouds, mountains and valleys were presented one by one.

Shangjietie was written in 744 (Tianbao three years), and Li Bai, Du Fu and Gao Shi visited the balcony palace of the Prince of Wu. Li Bai visited Sima Cheng Town. When he reached the balcony, he realized that Sima Cheng Town had passed away and would never see him again. I didn't see the man, but I saw his painting, and I wrote about the terrace on it. [3]

The above is the background, and then it is not difficult to understand what Li Bai wants to express.

The first two sentences directly describe the murals made by Master Sima. The mountains are high in water, magnificent in momentum and changeable.

The last two sentences are indirect descriptions. If it weren't for the master's sophisticated brushwork, I couldn't describe the magnificent scenery of Mount Wuwang to the world with my fresh and vigorous writing style. In other words, words are not as good as brushes, and I can't exhaust its beauty! Who is the clear and powerful pen? I think it refers to myself. Comparing his writing style with the master's brush is also in line with Li Bai's madness. After all, he really deserves to call himself clear and powerful. ).