Why is patting cucumber, an ordinary cold dish, also called chopping people before a knife?

Shooting cucumbers is called "people before chopping with a knife" because when making this cold dish, cucumbers are usually mashed with the back of a knife or chopsticks. This process is similar to cutting or hitting an ex-boyfriend with a knife, hence the name. In addition, there is a saying that in ancient times, the behavior of men chopping cucumbers was considered unlucky, so it is a humorous statement to call cucumber patting "the man before chopping with a knife".