Someone told him:

In the past, a man was born blind. He had never seen the sun, so of course he had no idea what the sun looked like. But he would like very much to know the shape of the sun, so he asked people with good eyes.

The blind man was very glad to hear this. When he returned home, he struck the copper plate and heard a ding-dong sound. Later, when he heard the toll of a bell, he thought it was the sun.

Another man told him:

"The sun is like a copper plate."

"The sun can give out light like a candle."

"This is the sun."

When the blind man returned home, he touched the candle, and remembered well its shape. One day, he touched a yue (flute) and said happily: