Among Liu Yuxi's three poets, what is the difference between Wei Zhuang and Shi Dazu's expression of swallows?

Yan Lai by Wei Zhuang: I bid farewell to my neighbor last year, but now I am stunned by the new thatched cottage. Bloom should ask each other about the language, not the village master.

Liu Yuxi's Wuyi Lane: weeds are blooming beside Zhuque Bridge, and the setting sun is slanting at the entrance of Wuyi Lane. Swallows under the eaves of Wang Dao and Xie An have now flown into the homes of ordinary people.

Wei Zhuang said in the second sentence: the thatched cottage is new, and it is not as good as before; Liu Yuxi's first two sentences express "the present is not as good as the past" through Wuyi Lane and wild grass flowers, and both poems are a comparison between the present and the past. Wei Zhuang and Liu Yuxi's swallows were all swallows of last year, but Liu Yuxi's swallows have added a layer of historical vicissitudes. The original Wang Xiejia has become the home of ordinary people, including the feelings of rise and fall now and now, and the ups and downs have changed.

At first reading, Wei Zhuang's poems are very similar to an ordinary pastoral poem. But this is not necessarily the case. You should know that Wei Zhuang lived in the late Tang Dynasty, with social unrest and shuddering. Zhu Wen usurped the political power of the Tang Dynasty and established the first dynasty of the Five Dynasties: Liang. Therefore, Wei Zhuang may use the new thatched cottage to represent the change of dynasties, and what the change of old owners may mean.

Shuang Yan by Shi Dazu combines the expression of swallows with the emotional behavior of characters. But comparing the swallows in this poem with those in Liu Yuxi and Wei Zhuang, we can still see some differences. The swallow in Shi Dazu has nothing too deep, just as an incompetent messenger; Liu Yuxi's Wang Mingxian has the feeling of modern rise and fall; The swallow in Wei Zhuang's Yan Lai seems to be hiding something. At the end of the two sentences, "bloom should ask each other, not the old owner of the village", seems to be absent, but it is as light as thick. More intriguing.

If Wei Zhuang's "Yan Lai" is regarded as an ordinary pastoral poem, just like Shi Dazu's "Shuang Shuang Yan", it is only about scenery and objects, which is obviously different from Liu Yuxi's.

? If Wei Zhuang's Yan Lai is regarded as a metaphor for Liang and Tang Dynasties, it will be much more brilliant. Does Wei Zhuang think so? This is not clear. The double context and double implication of poetry are its most fascinating features.