"and while one man guards it, ten thousand cannot force it" describes the sword gate, which means that the mountain is high and dangerous, and tens of thousands of people can't get in with one person holding the pass, which means that the terrain is very steep and strategic. It also describes that one person has the courage of ten thousand cannot force it, and one person blocks tens of thousands of people.
The source is Li Bai's Shu Dao Nan in the Tang Dynasty: "though Dagger-Tower Pass be firm and grim, and while one man guards it, ten thousand cannot force it." Jiange: Jiange, also known as Jianmenguan, is planted between the big and small Jianshan Mountains in Jiange County, Sichuan Province. Proud: the mountain is high and steep; Cui Gui: The sound is surrounded by Cui Wei, and it is tall. It is very dangerous to describe the terrain.
Extended information:
Difficulties in Shu Dao is the representative work of Li Bai, a great poet in Tang Dynasty in China. This poem imitates the old Yuefu theme, develops rich imagination by romantic means, and artistically reproduces the spectacular, abrupt, tough and rugged Sichuan Road and the majestic momentum that cannot be surpassed, so as to sing the magnificent scenery of the mountains and rivers in Sichuan, show the grandeur of the mountains and rivers of the motherland, and fully show the poet's romantic temperament and love for nature. The whole poem is 294 words, which is mixed with prose, uneven sentences, bold and free and easy, strong feelings, singing and sighing. There are many hidden pictures in the poem, whether it is the high mountains, the urgent water, the improvement of rivers and mountains, the desolation of trees and the danger of climbing mountains and cliffs, all of which are threatening, magnificent in weather and wide in realm, which embodies the artistic characteristics and creative personality of Li Bai's poems. Shen Deqian, a poetry critic in the Qing Dynasty, commented on this poem: "The strokes are vertical and horizontal, such as flying and moving, and thundering between the fingers."
Reference: Baidu Encyclopedia-Difficulties in Shudao.