Moral: Lao Yan's departure symbolizes the separation of husband and wife, relatives and friends.
Source: The word "old swallow" comes from "Yuefu East Flying Shrike Songs and Poems": "East Flying Shrike West Flying Swallow, Huang Li meets Weaver Girl."
"Lao Yan" refers to shrike and swallow, and "Lao" is the abbreviation of shrike, which has nothing to do with "hard work". The shrike belongs to the shrike family, a passerine bird, which looks like a sparrow. . "Lao" and "Yan" fly in different directions, so their posture is "flying separately" rather than "flying around". ? Shrike, commonly known as Hubra, is an insect-eating bird. Most of them live in hills and open woodlands, and they are common birds in China. Because it is more common, it is also written into the poem. Swallows took shrike into the poem. For example, there is a saying in Wang Shifu's "The West Chamber": "His song has not passed, my meaning has passed, and the shrike flies to the west." ? Shrike meets swallows, and they agree with each other. The identity of * * * becomes a new meaning. Under the sky of traditional poetry, shrike flies eastward and swallows fly westward in a hurry, and the instant meeting can't change the flying posture. Therefore, it is always too late to meet and too sick to leave. The shrike flying east and the swallow flying west together form a sentimental separation and become a symbol of no longer meeting. ? In ancient times, it was a metaphor for the separation of husband and wife and lovers. Now there is no meaning of husband and wife and lovers. It means that relatives and friends leave. ? Because most species of shrike in China belong to migratory birds, which migrate with the change of seasons, shrike has become synonymous with parting in the eyes of the ancients.