A king wished to honor a dervish.
"I'll give you a gift," said the king. "Tell me what you want!"
The dervish just laughed. "A slave doesn't give gifts to his master; the slave's life is already his."
This made the king angry. "I'm the king!" he shouted.
"You may be the king," replied the dervish, "but you are also the slave of my slaves, which makes me your master."
The king stared at him in bewilderment.
"I've mastered both anger and lust, making them my slaves," the dervish explained, "while you, though a king, are enslaved to them both."
Inspired by: The English prose version of Rumi in Tales from the Masnavi by A. J. Arberry.
Notes: This is told as an aside in story 37 of the book, which is about Luqman.