As a mullah, meaning a man of some education, Nasruddin was entitled to wear a turban, and he always wore the finest one that he could afford.  One day it happened that a poor illiterate man from the countryside came to see the mullah, holding a paper.  “Mullah,” he said, “I have received this letter–could you please read it for me?”

Nasruddin took the paper and stared at it for a long time, turning it one way and then another.  Finally he handed it back.  “I’m sorry,” he said to the man, “To lie is to place a stain on one’s eternal soul. I can’t read a single word of it.”

“You can’t read it?” the man said, astonished.  “Nasruddin, you are a disgrace to your turban!”

Nuruddin took his turban off and placed on the head of the other. “If you think the knowledge is in the turban, then here–read the letter for yourself!”