Chinese Fable： 打草惊蛇 - Beat the grass and startle the snake

Chinese Fable:Beat the grass and startle the snake 打草惊蛇
 

打草惊蛇【解释】：打草惊了草里的蛇。原比喻惩罚了甲而使乙有所警觉。后多比喻做法不谨慎，反使对方有所戒备。
【出自】：宋·郑文宝《南唐近事》：“王鲁为当涂宰，颇以资产为务，会部民连状诉主簿贪贿于县尹。鲁乃判曰：‘汝虽打草，吾已惊蛇。’”
【示例】：空自去“～”，倒吃他做了手脚，却是不好。 ◎明·施耐庵《水浒全传》第二十九回
【近义词】：操之过急、因小失大
【反义词】：欲擒故纵、引蛇出洞
【语法】：连动式；作谓语、定语、宾语；含贬义，多用于否定句
 

Long long ago, a county magistrate named Wang Lu worked in present day Anhui province, East China. Wang Lu was very greedy and took many bribes. One of his secretaries was equally corrupt, and often schemed for Wang Lu's deeds.

One day a man went to the magistrate to lodge a complaint against the secretary. The secretary's crimes were almost the same as the crimes the magistrate himself committed. Wang Lu was so frightened that he forgot his proper role in handling the case. Instead of issuing a judgment, he couldn't help writing these words concerning the complaint: "By beating the grass, you have startled me who am like a snake under the grass!"

The above story provided the idiom "Beat the grass and startle the snake". The original meaning is that punishment for someone can serve as a warning to others. But people now use the idiom to indicate that premature actions which put the enemy on guard.