In the past, a man was born blind. He had never seen the sun and had no idea what it looked like. Eager to know its shape, he asked people with good eyesight.
Someone told him, "The sun is like a copper plate."
The blind man was delighted. Returning home, he struck a copper plate and heard its ding-dong sound. Later, upon hearing the toll of a bell, he thought it was the sun.
Another person told him, "The sun gives out light, like a candle."
The blind man went home, touched a candle, and memorized its shape. One day, he touched a yue (a type of flute) and said happily, "This is the sun!"