Why Hijab?

One day a sheikh with his wife in Hijab and a non Muslim were traveling together in the train.
The non Muslim asked the sheikh: “Why do you people cover your wife from head to toe?”
The sheikh started thinking… suddenly he took a fruit from his pocket cut it half with knife.The sheikh asked the non Muslim: “Do you know what this is?”
The non Muslim responded: “hmmm…yum yum…Yes I know, this is fruit.
The sheikh then replied: “No….this is my fruit, while it was in my pocket your mouth didn’t water but as soon as I took it out and cut it, you wanted to taste it, similarly when a woman is covered from head to toe, no one will think about her but if she removes her Hijab then every one will desire her.
SUBHANALLAH