What is the main idea of the first four sentences of Wang Wei's "Mountain Residence in Autumn Night"?

The empty mountain is bathed in a new rain, and the arrival of night makes people feel that it is early autumn.

The moon is clear and clear, and the clear spring is flowing.

"The empty mountain after the rain stands in the autumn evening." The poem clearly says that there are female fishing boats, but the poet writes "the empty mountain". This is because the dense trees on the mountain cover up the traces of people's activities. The so-called "there seems to be no one on the empty mountain, but I think I heard a voice" (Chai Lu). Because there are few people here, "Who knows that there are people coming in the gorge, and outsiders only see the empty mountains and thick clouds" ("Peach Garden Tour"), naturally someone comes to Mount Fuji. The word "empty mountain" points out that besides, it is like a paradise. In the early days of Shan Yu, everything was new. It was early autumn evening. It is conceivable that the air is fresh and the scenery is wonderful.

"Moonlight in the pine forest, crystal stone in the stream." It was dark, but there was a bright moon in the sky. The flowers have withered, but there are pine trees covered. The mountain spring is clear, flowing through the rocks, like a pure white plain, shining in the moonlight, vividly showing the quiet and clear natural beauty. Wang Wei's Ode to the Four Saints on Economy once praised the noble sentiments of the two sages, saying that "there is no evil wood in the shade, and drinking water must be extreme." The poet himself is such a noble-minded person. He once said: "It is better to drink its water and rest in the wild forest, instead of sitting on the beam and seeing the princes in the rugged." This month, pine trees and clear springs on rocks are exactly the ideal realm he pursues. These two sentences are picturesque, free and easy, and have little strength.