What does the solitary sail in the Yangtze River skyline mean?

"Yellow Crane Tower Farewell to Meng Haoran in Guangling" Tang Dynasty. Li Bai

The old friend bid farewell to the Yellow Crane Tower in the west,

Fireworks descended from Yangzhou in March.

The shadow of the solitary sail in the distance is gone in the blue sky.

Only the Yangtze River can be seen flowing in the sky.

Note:

Gufan: a boat.

End of the blue sky: disappear in the blue sky. Exhaust: disappear.

Wei: only.

Skyline flow: flowing to the horizon. Skyrim: The horizon.

"The shadow of the lonely sail is gone in the blue sky, and only the Yangtze River can be seen flowing in the sky." On the surface, these two poems seem to describe scenery, but in fact they have a distinct image of the poet. "Lonely sail" by no means means that there is only one sailboat on the vast Yangtze River, but that the poet's entire attention and emotion are only concentrated on the sailboat on which his friend is riding. The poet saw him off by the Yellow Crane Tower and watched the boat on which his friend was riding hang up its sails and gradually get farther and farther away. place, but the poet still stood for a long time, watching the river flowing to the sky, as if he wanted to entrust his affection to the river, accompany the boat, and send his friends to their destination. These two lines of poetry express the deep friendship between Li Bai and his friends, but the word "friendship" cannot be found in the lines.

The poet cleverly placed his deep feelings of farewell in the dynamic description of natural scenery, completely blending the emotions and scenery together, truly speaking without saying anything but leaving an endless aftertaste...