What does the first two sentences of Yanwu's early autumn poem in Juncheng describe? What's the moral?

In September this year, in the late autumn, the Tubo army invaded and fought with Tang Jun in the border area. The clouds are dignified, covering the peaks, and a lonely moon quietly releases cold cold light.

is a picture of the cold war between Tang Jun and the enemy.

its moral is that the war between the enemy and ourselves is imminent and urgent.

here, we mainly use the technique of feeling in the scenery.