Excuse me, what does it mean that Qingxi runs through Bishantou, with clear water and 30 miles of red dust in autumn?

Appreciating the autumn moon, the clear water flows through Bishantou, and the empty water is fresh in autumn. Three miles away from the world of mortals, white clouds and red leaves are two long. This is a seven-character quatrain written by Cheng Hao, a Dali scholar in the Northern Song Dynasty. If you study it carefully, you will find that there is no poem about the moon, but moonlight is everywhere. Please see, the clear stream flows slowly around the castle peak, and the blue sky is reflected in the water, so clear and pure, and the two blend into one color, just like the landscape of Guilin. If there is no bright moonlight between heaven and earth, how can poets appreciate the clarity of water, sigh the beauty of mountains and express their feelings for the clarity of empty water in autumn night? Look down. In the third sentence of the poem, the poet's sense of being free from vulgarity and relaxed and happy comes from watching the moonlight in Qiu Guang. The last sentence "white clouds" and "red leaves" is not only a symbolic illusion, but also a true sight of the mountains and forests that the poet saw under the autumn moon. Symbolically speaking, the free floating of "white clouds" and the elegant complacency of "red leaves" are not the portrayal of the poet's leisurely and quiet mood? From the perspective of real life, you can actually see white clouds and red maple leaves at night, which also shows how bright the moonlight is! Think about it, there are lush green hills, clear streams flowing, or you can hear a few crisp birds singing, there are red maple leaves on the roadside, there are white clouds in the sky, walking on a cobblestone road, and the bright moonlight shines softly on you. What a wonderful feeling. There is no moon in the whole article, but the moon is everywhere. The scenery is lyrical, simple and natural, which can be called Si Kongtu's words: "No word, romantic."