As beautiful as the setting sun is, it is extremely cold at high places. The first couplet is from a poem by Li Shangyin, and the second couplet is from a poem by Su Shi. What explanation is used?

There are some special ways of writing couplets. One of them is to take two sentences from ancient and modern poems, songs and poems.

For example, "The sunset is infinitely beautiful, but it is not cold at high places." The first couplet comes from The second couplet of Li Shangyin's poem comes from Su Shi's poem,

This is called "Collected Sentences".

"Jiju": one of the ways of composing poetry in the old days. Interpret the poems of the previous generation, family, or several families and put them together into a poem. The earliest extant collection of verses is the "Seven Classics Poems" by Fu Xian of the Western Jin Dynasty.