During the Southern Tang Dynasty, one of the Ten Kingdoms of the Five Dynasties period, Wang Lu served as the magistrate of Dangtu County. Already known for his misconduct and shady dealings, Wang Lu used his official power to engage in corruption, embezzlement, and extortion, amassing considerable wealth. Seeing their magistrate's behavior, the county officials at all levels tacitly colluded, accepting bribes and oppressing the people without restraint. The common folk could only shake their heads and sigh, their grievances filling the air. Today, this story reminds us that unchecked corruption at the top inevitably corrupts the entire system.
Later, someone filed a complaint accusing Wang Lu's chief clerk (equivalent to a modern secretary) of embezzlement and bribery. When Wang Lu took the complaint and opened it, he couldn't help but shiver inwardly. The charges against the clerk were all solid facts, strikingly similar to his own misdeeds—some even committed under his connivance. Even more alarming, many of the crimes implicated him directly. Though frightened, Wang Lu felt fortunate that the complaint had landed in his hands; had it fallen to someone else, his own crimes would be exposed and his position as magistrate lost. The more he thought about it, the luckier he felt, and he casually scribbled eight characters on the document: "Though you strike at the grass, I, the snake, am already startled."
These eight words mean: "Though you strike only the grass, I, the snake hidden within, am already startled and on guard."
"The idiom 'Beat the Grass to Startle the Snake' originally meant punishing someone while alerting others in similar situations. Now it describes acting carelessly, causing the target to detect one's secret intentions and prepare accordingly."
Source: Lang Ying (Ming Dynasty), *Qixiu Leigao*
Meaning of the Idiom: Later, the Chinese idiom "打草惊蛇" came to describe acting carelessly, causing the target to detect one's secret intentions and prepare accordingly.