Behlool simulated madness, though he was not mad.  Junaid a scholar and Sufi or repute, knew him very well.  One day as they met, Junaid requested him to give him some counsel and admonition.
 
        "You do no need any advice.  You are a well known Aalim." Behlool said.

        But Junaid insisted.  Behlool gave in and said: "Well, I shall ask you three questions.  If you answer them correctly, you will be advised."

        And then he proceeded to ask:
        "Do you know how to talk?"
        "Do you know how to eat?"
        "Do you know how to sleep?"

        Junaid found these simple.  He said:

        "I know how to talk.  I talk with a low voice, politely and to the point, so that the listeners are not at all offended.  I eat after having washed my hands, say Bismillah before I commence, and chew the food properly.  When I finish, I thank Allah.  Before I go to sleep, I do my Wudhu and retire to a clean, Pak, bed.  Then I bear witness to my faith and sleep."

        "Well," Behlool said, "It is no use talking softly if it is a lie.  It is all the worse.  When talking, one must ensure that one speaks truth.  That is the cardinal point.  And when eating, remembering Allah over a food which is Haram, forbidden or usurped, has no meaning.  You have to ensure that what you eat is Halal or that you are not misappropriating the funds of an orphan, a widow, a fellowmen.  And what is the use of sleeping with Wudhu and all the recitations if your heart is full of malice, jealousy and enmity towards your Momin brother.  He who sleeps with a clean heart sleeps a religious man.  Do you understand?  These are the principles.  The rest are all secondary virtues."
 

Reference:
Pearls of Wisdom.  A String of Incidents in the History of Islam.  The World Federation of Khoja Shia Ithna-Asheri Muslim Communities. Pages 37-38.