It happened once upon a time that a man came to the house of Mullah Nasruddin late at night, asking him to please write a letter for him.

“You know I am a poor man, Mullah,” said the man, “so please do not charge me much for this.  What does writing cost you? Do it as a favor to God. He will surely reward you for the kindness.”

The Mullah was already preparing for bed, and was not very enthusiastic to write a letter, and so, as he rummaged around by lamplight for his writing materials, he said to the man, “Well, that depends.  Where is the letter going?”

The man looked at the Mullah in astonishment.  “Where is it going?  To Istanbul.  What does that have to do with it?”

“Ah, well,” said the Mullah, “the problem is this, my friend.  As a favour to God, I will write the letter for free–and if He rewards me or not is His affair.  But I must tell you that my writing is purely my own, and no one else can read it.  So I must go with the letter to read it to the recipient.  And if I have to travel all the way to Istanbul, you will have to pay my journey!”

A moment later the visitor was gone, and the Mullah’s lamp was extinguished.