Nasrudin didn’t have a house, of course. He was only trying to show the people how dumb they were. When the people asked the long-haired man for proof about what he was saying, what did he do?
He showed the people a book that he wrote himself. But just because someone writes their words in a book, it does not mean that they’re automatically true. The long-haired man just put whatever he had to say on paper. What kind of proof is that?
The dumb people thought that the man’s own book was enough proof that whatever he said was right. Nasrudin put a brick on the table to prove he had a house. But anyone can bring in a brick and say that, even if they don’t really have a house, like Nasrudin.
The people should have known that proof for something has to come from a different person or thing. Otherwise, it may be just one person fooling you over and over. This is good advice: always look for proof, and don’t just take someone else’s words by themselves. That is the best way.