The blind man told the deaf that he saw the dumb singing. What does this mean?

This is a metaphor, which means that there is something wrong with the transmission and understanding of information. Both the blind and the deaf have their own limitations. They can't accurately understand the surrounding situation, while the dumb can't express their ideas. Therefore, even if the blind tell the deaf that they saw the dumb singing, in fact, the blind can't see and the deaf can't hear, so they can't understand and transmit the information accurately. This metaphor can be used to describe the difficulty of information transmission and understanding in communication.