Whereupon he began to flaunt his supposed power and said, “You and I shall be wrapped in a reed mat after our bodies have been coated with sulfur.” I replied, “Then rise,” and I kept pressing him to carry it out. He stretched out his hand as though to remove his tunic, but I said, “No— not until you bathe with hot water and vinegar.” As is their habit, he feigned confusion and said, “Whoever loves the emir, let him bring some wood”—or he said, “a bundle of firewood.” I said, “That only drags matters out and scatters the crowd without achieving the goal. Rather, let a lamp be lit; after we have washed, I will place my finger in it and you place yours. Whoever’s finger is burned, upon him be Allah’s curse—or, I said, he is the defeated one.” When I said this, his color changed and he was humbled. — End (1)

The point of relating this incident is to show that such charlatans deceive people with these subtle tricks.