This is a pair of antithetical couplets. Take apart the components of a word and do the problem.
There are two sources:
one
Zheng Banqiao likes to have morning tea in the teahouse. One day, I went to the city gate to have morning tea. Because of the crowd, Zheng Banqiao's robe was hung on a woodcutter's firewood. Embarrassed, the woodcutter put down the firewood and apologized to Zheng Banqiao. Seeing that Zheng Banqiao was a scholar, he said, "I have a pair of couplets. If you can make a couplet, I'll give you a new dress, ok? " Zheng Banqiao believes that reciting poems is his own strength. Why should he be afraid of a mere woodcutter? So I agreed.
The woodcutter's couplet is: "This wood comes from the mountain." This couplet sounds not difficult, but when you think about it carefully, it is a reduplicated couplet, which is very wrong! Zheng Banqiao thought for a long time and couldn't figure out the bottom line, so he had to give up and waved the woodcutter away.
Zheng Banqiao went to the teahouse and thought hard all day, but he couldn't figure out the bottom line. It's already dusk, and he can't go without it. So I stood up and looked out of the window, and the smoke on the roof of every household filled the air. What a beautiful scenery! You can only see it at dusk! Inspired by touching the scene, the next couplet has: "Because of the fire, it is smoky in the evening."
Second:
It is said that when Emperor Qianlong went down to the south of the Yangtze River and crossed the boat, he saw the lush mountains on both sides of the river, so he came up with a couplet: "This wood was picked from Chaishan Mountain", and Ji Xiaolan, who accompanied him, was resourceful and pointed out the smoke from the kitchen in the twilight of the people in the water town: "There are many smoke from the fire."
However, these two statements have also been questioned by some people. They think that before the simplification of Chinese characters, the word "smoke" was called "smoke", and this couplet should have appeared after the simplification of Chinese characters, and it is a work of modern people.
However, a historian said: Before the simplification of Chinese characters in 1950s, many simplified characters (so-called vulgar characters) had become popular among the people. The principle of simplification of Chinese characters is "words without deeds", which only affirms the simplified characters that predecessors have become accustomed to and does not create new simplified characters. The word "smoke" born of fire should have existed since ancient times. So this couplet is not necessarily the work of the ancients.