The sky is like a vault. What does it mean to cover all the fields in a cage?

"The sky is like a vault, and the four fields are covered with cages" refers to the sky in Chilechuan, which is connected with the earth on all sides and looks like a felt tent where herders live.

This poem comes from the "Chile Song" in the Southern and Northern Dynasties.

The original text is as follows:

Chilechuan at the foot of Yinshan Mountain. The sky is like the sky, and the cage covers four fields.

The sky is gray and wild. See cattle and sheep when the wind blows.

Explanation:

The vast plain of Chile, just under the mountains thousands of miles away, is like a dome tent in the sky, boundless and covered with Yuan Ye in all directions.

sky blue

The word qióng lú refers to the felt tent where the Mongols live. It is made of felt, with a raised center and drooping around, and is shaped like the sky, so it is called Qió ng Lú.

The sky is like a lid, covering the earth. This is why the ancients used to think that the sky was round and the place was artificial, just like a bowl buckled on the ground.