"In the old society, Wang Xieyan flew into the homes of ordinary people." The author suddenly turned his brush strokes to the flying swallows nesting over Wuyi Lane, so that people could identify them along the flying direction of swallows. Nowadays, ordinary people live in Wuyi Lane. In order to make readers clearly understand the poet's intention, the author points out that these swallows flying into people's homes used to be old swallows living on the eaves of Wang Xiequan's high hall. The word "old times" gives the swallow the identity of a historical witness. The word "ordinary" especially emphasizes how different the residents today are from the past. From this, we can clearly hear the author's infinite feelings about this change.
It means that things are changing and developing, and we should look at the problem from a developmental perspective.