Boy Yu's family had a strict rule: "Every child must follow the teachings of Zengzi and examine themselves daily: Have I been loyal when helping others? Have I been honest with friends? Have I reviewed my lessons thoroughly?" Breaking the rule meant five strikes with a cane. Each evening, the family head checked compliance. Since Boy Yu's father had passed away, his mother took on this duty.
The young boy had few opportunities to help others, and his friends were merely classmates at the village school. Young Boyu's most frequent infraction was the third rule—not studying his lessons diligently. Yet Boyu was a good child who never caused trouble outside; after school, he would finish his homework before playing, so in a whole year, he rarely felt the sting of the cane.
When Boyu grew up, he worked as a clerk in the county office, handling documents with such precision and clarity that he often earned praise from the magistrate.
The trouble lay in the second family rule: because his official duties required him to interact with people from all walks of life, it became difficult to distinguish friends from mere acquaintances. Moreover, among those he dealt with, some had broken the law, and Boyu would act impartially, punishing them according to the statutes. Major issues of right and wrong were easy to judge, but when it came to trivial matters, punishing someone by law—was that considered offending a friend or not? It was impossible to say.
Though Boyu had long since grown up and managed his own affairs, he still strictly followed the family rule, reporting his daily successes and failures to his mother each day without fail.
The white-haired old lady, sharp-minded and robust, listened to her son's reports every night without fail. When she judged he had broken family rules, she would take a heavy, long rosewood cane from a case on her desk and, without mercy, strike her kneeling son's buttocks five times.
"Mother, today I broke the family rules. A friend asked me about official matters at the yamen, and I thought it was a public affair that shouldn't be shared, so I lied and said I didn't know. But I actually knew the truth, and this goes against 'being trustworthy with friends.'" Boyu, fearing his hard-of-hearing mother couldn't catch his words, raised his voice and shouted loudly.
"Since it's official business not meant for outsiders, you should have refused him outright instead of using deception to brush him off. Kneel down, and let me bring out the family rules..." the mother said slowly, word by word.
This family discipline was actually a system of reminders and supervision; the cane would strike the body, but not too heavily.
The old woman, trembling, raised her walking stick and struck five times.
Bo Yu burst into tears and fell to the ground, unable to rise.
"Strange, I've used the family discipline many times and never seen you cry once. What's wrong this time?"
"Mother, in the past when you struck me with the cane, it had real force—one, two, three, four, five, and it was over quickly. These last two or three times, you raise the cane more and more slowly, merely brushing me a few times before stopping. Mother has aged, her strength has faded, and I, your son, feel this keenly—that is why I weep in sorrow..."
"Bo Yu Weeps at the Cane" is used to describe filial children who care for their aging parents' health.
Source: *Garden of Stories*, Chapter "Establishing Foundations"
Meaning of the Idiom: Later, the Chinese idiom "伯俞泣杖" came to describe filial children who care for their aging parents' health.