In the Han Dynasty, a man named Ying Shao wrote a book called *Comprehensive Meaning of Customs and Habits*. This book records what he called "cases where people in the world see strange things, become frightened, and harm themselves." The idiom "A Bow's Shadow in the Cup" describes a strange incident encountered by his grandfather Ying Bin.
On the summer solstice, County Magistrate Ying Bin invited his chief clerk Du Xuan for a drink. In the hall, a red bow hung on the north wall, and as light refracted, its shadow in Du Xuan's cup looked exactly like a writhing snake.
When Du Xuan saw it, he was so terrified that goosebumps rose all over his body, and he lost all desire to drink. But since he was at his superior's home and the wine was offered by his host, he dared not refuse, so he steeled himself and forced it down. When the servant tried to refill his cup, he made an excuse and declined.
Returning home, Du Xuan trembled at the mere thought of the snake in his wine cup, convinced it had slithered into his stomach and was writhing inside him, causing unbearable chest and abdominal pain that made even eating and drinking excruciatingly difficult.
His family grew deeply worried and quickly summoned a physician to treat him. The doctor exhausted every method, administering various medicines, yet his condition showed no improvement.
One day, Ying Bin visited Du Xuan at home and found him gravely ill. Du Xuan recounted the events of that drinking session, insisting, "That snake is still in my stomach, and I fear it will keep causing trouble inside me."
Ying Bin offered a few words of comfort and then returned home, sitting in the hall deep in thought, utterly baffled as to how the snake had gotten into Du Xuan's wine cup.
Suddenly, the red bow hanging on the north wall caught his attention. He examined it repeatedly, then sat in Du Xuan's original seat, took a cup of wine, and placed it in the same spot. A miracle occurred: the bow's shadow appeared in the cup, wriggling like a snake.
Ying Bin suddenly realized the truth and immediately sent a carriage to bring the ailing Du Xuan to his home. He seated Du Xuan in his original position, poured a cup of wine, then pointed at the "snake" in the cup and said, "The snake you saw in your cup is merely the reflection of that bow hanging on the wall—nothing more. Now you can rest easy!"
After Du Xuan examined the cup and saw the reflection for himself, his mind immediately relaxed, and his illness soon healed completely.
Later, people used the idiom "Seeing a Snake in a Cup" to describe being overly suspicious and frightened by one's own illusions.
Source: *Fengsu Tongyi*, "Strange Spirits"
Meaning of the Idiom: Later, the Chinese idiom "杯弓蛇影" came to describe being overly suspicious and frightened by one's own illusions.