What is the supplementary irony of raising pigs like a mountain and killing rats first?

Legend has it that this is a couplet written by a scholar to the rich man-the first couplet is "Raising pigs is like a mountain, and the mouse's head dies", the second couplet is "Brewing jars can make vinegar jars sour", and the horizontal couplet is "Being ill and getting rich less". The rich man read it and praised it again and again. People laugh at it when they read it. Why? Look at how they read it-the rich man reads: raise a pig like a mountain, and the mouse will die. A good wine jar is sour with vinegar. Many people, few diseases, wealth. People read: raising pigs is as big as a mountain mouse, and its head is dead. Wine vats are good for vinegar, but the jar is sour. Many people are ill, but few are rich. The rich didn't see the cleverness and irony implied in this couplet. People laughed at the rich man's stupidity.