(2) Hongyan: Hongyan is a large migratory bird, which moves southward every autumn. Traveling often causes homesickness and sadness. For example, Xue Daoheng, a native of the Sui Dynasty, wrote: "People return to yan zhen and think before spending." I had the idea of returning to China long before the flowers bloomed. But when the geese returned to the north, people had not returned home. When the poet was an official in the Northern Dynasties, the Southern Dynasties sent envoys to Chen State to write this homesick poem, which was subtle and tactfully. As a messenger, Hongyan is also widely used in poetry. For example, "The geese cross and don't answer me, and the rivers and lakes are full of rain" (Du Fu's "Heaven is not pregnant with Li Bai").
Liu: Fold the willow to say goodbye. "Liu" and "Liu" are homophonic, and folding Liu means leaving each other. Therefore, the ancients had the custom of folding willows to bid farewell, so "willows" meant parting. Therefore, in Yulin Ridge, Liu Yong expresses the sadness of parting by saying "Where to wake up tonight, Yang Liuan, where the breeze fades away".