Yue Guang was very hospitable. One day he invited a friend to have a drink in his hall.

While drinking, his friend thought he caught a glimpse of a small snake swimming around in his cup. Though disgusted, he swallowed the wine down, but the thought of the snake nauseated him. As soon as he got home, he fell ill.

Yue Guang hurried to his friend's home and told him about this. As soon as his friend came to understand that it was not a snake but the reflection of a bow in his cup, he got over his illness at once.

After a few days, Yue Guang heard about his friend's illness and its cause. He thought that there couldn't be a snake in the wine cup. So he went to inspect the place where they had the drink and eventually found the cause: on the wall of the hall hung a colourful bow, the shadow of which happened to throw exactly at the place where his friend had put his wine cup.