At that time, the magistrate was an official who donated money, and the money used to buy this position was exaggerated enough. He became a magistrate, but he didn't have real talent and knowledge, so Zheng Banqiao didn't like him at all, and he didn't feel the need to go out of the city to meet him, but he didn't expect the magistrate's adult to come to Zheng Banqiao's trouble.
Magistrate adults came to the county yamen, the thought of Zheng Banqiao refused to go out of the city to meet this matter, he was very unhappy. So the magistrate became more and more angry at the welcome banquet. Just then, a policeman served a plate of river crabs, and the magistrate had a brainwave and came up with a bad idea. If I write a poem with this river crab, if he can't write it, then I have a legitimate reason to humiliate him in front of everyone, and let me get out of this anger in my heart, thinking that he will point to the river crab with chopsticks and say that this creature is rampant in the river.
Zheng Banqiao knew that he wouldn't suddenly have such a good purpose and wanted to show everyone his talent. He thought about it and made a poem effortlessly, reciting the benefits of this river crab for everyone. Zheng Banqiao answered the magistrate's question easily, which made the magistrate feel ashamed and very angry.
The above story only represents my personal opinion. Please forgive me if there is any mistake.