What does loquat and pipa joke give people?

Shen, a scholar in Ming Dynasty, once received a box of gifts from a friend, which contained a letter. The letter said, "I sincerely hope you can accept the pipa." He opened the box and saw a box of fresh loquat. Shen couldn't help laughing and wrote back to his friend, saying, "Lynn, thanks to the pipa, I hope it will be silent when you listen, and delicious when you eat." My friend was ashamed when he read the letter, so he wrote a doggerel: "Loquat is not this pipa, because he can't read much." If the pipa can blossom and bear fruit, all the pipes in the city will be open. If the pipa can bear fruit, all the flutes in the city will blossom. "Loquat and pipa have different meanings. My friend played a joke on Shen.