In ancient China, mandarin ducks were first compared to brothers. There are poems in "Selected Works" such as "In the past we were mandarin ducks and ducks, now we are participating in business". This is a farewell poem between brothers. Zheng Feng, a native of Jin Dynasty, wrote four poems in "Reply to Lu Shilong's Poems". The preface of the first poem "Mandarin Duck" says: "Mandarin ducks are beautiful and virtuous people. There are two sages flying together to Dongyue." The mandarin duck here is a metaphor for Lu Ji and Lu Ji. Distant brother's.
The use of "mandarin ducks" as a metaphor for husband and wife was not seen until the Tang Dynasty poet Lu Zhaolin's poem "The Ancient Meaning of Chang'an". There is a line in the poem "I would like to be a mandarin duck but not an immortal", which praises the beautiful love. After that, some literati followed suit.
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