Once a dervish was sitting in a corner of a marketplace, reciting with great concentration the name ‘Allah’. A passerby heard him, and stopped to ask, “What is ‘Allah’?

The dervish replied, “I don’t know.”

“If you don’t know Him,” said the other, “why do you take His name?”

“Very well,” said the dervish. “Then please tell me, whose name should I take?”