Slap

One day Mullah Nasruddin was walking on the street, when a total stranger came up to him and slapped him on the back of his neck. 
The Mullah demanded some kind of rectification.
But the man was unapologetic.
He had thought the Mullah was a good friend of his, whom he was accustomed to greeting with such gesture.

'It is not an incidence of great significance,' he said to the Mullah `I thought you were my friend, I shouldn't be paying for such a small mistake.'
Mullah Nasruddin was not convinced.
He was wronged and he had to receive the damages.
Since the discussion was going nowhere, they decided to consult the kadi.
However, unbeknownst to the Mullah, the man and the kadi were friends.

The kadi listened to them both, and although it looked like the Mullah was right, he was still determined to get his friend out of this without having to pay a penalty.

'Mullah is right,' the kadi said, winking to his friend, `you have to pay him a gold coin.'
The friend, reassured with kadi's wink, said that he didn't have a gold coin on him but if they waited a few minutes, he would go and get it.
Kadi allowed him to go fetch the money and Mullah Nasruddin started to wait.
After waiting quite a while, and recalling the familiarity between the kadi and the man, the Mullah figured out that he was tricked and that the man was never going to come back.
He approached the kadi and startled him with a forceful slap on the back of his neck.

`Mullah, what did you do that for?' the kadi said in pain.

`Kadi, I am a little late for my errands, I can't wait any longer. When the man comes back, you take the gold coin!'