Empress Ma, wife of Emperor Ming of the Eastern Han Dynasty, was the youngest daughter of Ma Yuan, a founding general. Known for her learning, courtesy, generosity, and frugality, she earned deep respect throughout the court.
Emperor Ming of Han had a son named Liu Da, born to Consort Jia, but Empress Ma raised him as her own, devoting herself to his care. When Emperor Ming passed away, Liu Da ascended the throne, becoming known historically as Emperor Zhang.
After Emperor Zhang ascended the throne, he sought to repay Empress Dowager Ma for raising him by honoring her and repeatedly offering to ennoble her three brothers, Ma Liao, Ma Fang, and Ma Guang. However, the Empress Dowager, acutely aware that many imperial relatives were receiving undeserved rewards and living extravagantly, refused the emperor's requests with concern, saying, "I cannot allow my family to become another example of undeserved privilege."
Later, when Mother Ma passed away, the three Ma brothers built her tomb higher than the ritual regulations allowed. Upon learning this, Empress Dowager Ma immediately sent a messenger to her brothers, commanding, "You must rebuild the tomb to comply with the proper standards."
Under the empress dowager's urging, Ma Liao was careful with his words and deeds, but his son Ma Yu was reckless, hoping his father would ride the empress dowager's favor to rapid advancement and bring him along. When things didn't go his way, Ma Yu constantly complained. Ma Liao knew his son was wrong but did nothing to discipline him.
At that time, Ma Liao's close friend Yang Zhong saw this situation and wrote to advise him: "In the early years of our dynasty, many feudal lords failed to discipline their sons and brothers, who then violated the law, leading to the ruin of their states and families. How can you not face the deep abyss and tread on thin ice, taking their fates as a warning?"
Despite Yang Zhong's warnings, Ma Liao remained unmoved. When Empress Dowager Ma died of illness, the Ma brothers began to lose imperial favor. Ma Yu, seething with resentment, secretly wrote a letter slandering the court behind his father's back. Once discovered, Ma Liao and his two brothers were forced to return to their fiefdoms.
After returning to his fiefdom, Ma Liao subjected Ma Yu to brutal torture, but the defiant Ma Yu refused to confess and died from his injuries. A few years later, Ma Liao himself passed away in sorrow.
Later, people used the idiom "Approaching the Deep, Treading on Thin Ice" to describe being extremely cautious in one's actions.
Source: *Book of the Later Han*, "Biography of Yang Zhong"
Meaning of the Idiom: Later, the Chinese idiom "临深履薄" came to describe being extremely cautious in one's actions.