In the village where Mullah Nasruddin lived, it was a well known fact that ageing vinegar, just like ageing wine, could produce miracles, turning something harsh and ordinary into something spectacular.

Once it happened that a friend came to Nasruddin and said, “Mullah, I have heard it said, but God knows the truth, that you have a barrel of some very old vinegar.”

“Yes,” said the Mullah, “I do.”

“And I have heard,” said the friend, “that it has attained the extraordinary age of forty years!”

“Yes,” said the Mullah, “it has.”

“Then I beg you, Mullah,” said the friend, “give me a little.”

“No,” said the Mullah, “I won’t.”

“But Mullah, we are friends! And I need it to prepare a certain medication. Just a little!”

“If I gave some to everyone who asked,” replied the Mullah, “do you think it would have reached the age of forty years?”