During the Han Dynasty (206BC-220AD), there was a county magistrate called Ying Chen. One summer day, he invited his secretary Du Xuan to his house and treated him to wine. On the north wall of the hall hung a red bow, which was reflected in Du Xuan's cup. Du Xuan took the reflection for a squirming snake. He was very frightened but dared not turn down Ying Chen's offer because Ying Chen was his superior. He swallowed the wine with his eyes closed.
Back home, he felt so painful in his chest and stomach that he could hardly eat and drink anymore. He sent for the doctor and tried many medicines, but nothing could cure him.
When Ying Chen came to Du Xuan's home and asked him how he became so ill, Du told him that he drank the wine with a snake in his cup the other day. Ying Chen felt so puzzled about that. He returned home and contemplated it but couldn't find an answer. Suddenly, the red bow on the north wall caught his eye. "That's it!" he shouted. He immediately sent his man to fetch Du Xuan. He seated Du Xuan where he sat before and offered him a cup of wine.
Du Xuan saw the snake-like shadow again. Before Du was scared out of his wits again, Ying Chen pointed at the shadow and said, "The 'snake' in the cup is nothing but a reflection of the bow on the north wall!"
Now that Du Xuan knew what it was, he felt much easier. His illness disappeared the next moment!
This story was later contracted into the idiom, "mistaking the reflection of a bow in the cup for a snake." We use it to describe someone who is very suspicious.
bēi gōng shé yĭng
杯弓蛇影
在汉朝，有个县令名叫应郴。有一年夏天，他请主簿（办理文书事务的官员）杜宣来家里饮酒。酒席设在厅堂里，北墙上悬挂着一张红色的弓。由于光线折射，酒杯中映入了弓的影子。杜宣看了，以为是一条蛇在酒杯中蠕动。他非常害怕，但县令是他的上司，所以不敢不饮。他只得闭着眼睛喝了几口。
回到家里，杜宣只觉胸腹部疼痛异常，难以忍受，吃饭、喝水都非常困难。他赶紧请大夫来诊治。他服了许多药，但病情还是不见好转。
当应郴到杜宣家中，问他怎么会闹病的，杜宣便讲了那天饮酒时酒杯中有蛇的事。应郴觉得非常奇怪。他回到家，反复思考，就是弄不明白杜宣酒杯里怎么会有蛇的。 突然，北墙上的那张红色的弓引起了他的注意。“原来是这样! ”他大喊道。应郴马上命人把杜宣接来，让他坐在原位上，并递给他一杯酒。
杜宣又看到了那像蛇一样的影子。趁他还没被吓得魂飞魄散，应郴指着那倒影说：“你说的杯中的蛇，不过是墙上那张弓的倒影罢了！”
杜宣弄清原委后，感觉轻松多了，病也立刻就痊愈了。
这则故事后来演化为成语“杯弓蛇影”，用以形容那些非常多疑的人。
liào shì rú shén
料事如神
predict like a prophet; foretell with miraculous accuracy; foresee with divine precision
