Poetry describing martial arts

Once upon a time there was a man who filled grains in an urn. The camel enters the urn to feed the grain, but its head cannot come out. The master feels worried and has nothing to do. An old man came to talk to him and said, "Don't worry, I have something to teach you." The master asked urgently, "What's the method?" The old man said, "You should cut off the camel's head and you can do it yourself." The master thought it was wonderful. Then according to his words, he cut off the camel's head with his knife. He killed the camel and then broke the urn again. He was so idiotic that he was laughed at by the world.

Once upon a time, there was a man who was buried in an urn▼