Metaphor - "Mistake the shadow of a bow in one's cup as a snake"

杯弓蛇影 bēi gōng shé yǐng Mistake the shadow of a bow in one's cup as a snake -- a false alarm (self-created suspision). The metaphor of it is to make a crack to those who are always suspecting something so as to agitate himself.

Story:

One day, 应郴 invited 杜宣 to drink wine in his home. 应郴gave杜宣 a cup of wine. Since a bow was hanged on the wall against杜宣, the reflection of bow in wine is just like a snake. 杜宣 had to drink this cup of wine, because 应郴 was superior to him. After杜宣 came back to home, he suspected that he had drunk snake so he felt uncomfortable all the day. Some days later, when 应郴 knew that杜宣 was sick, he explained to him that it was just the reflection of bow. Then 杜宣 knew the reason and got well soon.

"Mistake the shadow of a bow in one's cup as a snake "