قال الخليل بن أحمد : الرجال أربعة، رجل يدري ويدري أنه يدري فذلك عالم فاتبعوه، ورجل يدري ولا يدري أنه يدري فذلك نائم فأيقظوه، ورجل لا يدري ويدري انه ل… - Al-Ghazali

The learned man who does not act up to his knowledge is like a patient who describes the qualities of a medicine without using it or like a hungry man who describes the taste of a food without eating it.

"The deceitful character of the world comes out in the following ways. In the first place, it pretends that it will always remain with you, while, as a matter of fact, it is slipping away from you, moment by moment, and bidding you farewell, like a shadow which seems stationary, but is actually always moving. Again, the world presents itself under the guise of a radiant but immoral sorceress, pretends to be in love with you, fondles you, and then goes off to your enemies, leaving you to die of chagrin and despair. Jesus (upon whom be peace!) saw the world revealed in the form of an ugly old hag. He asked her how many husbands she had possessed; she replied that they were countless. He asked whether they had died or been divorced; she said that she had slain them all. "I marvel", he said, "at the fools who see, what you have done to others, and still desire you." This"

"قال سهل التسترى " للعالم ثلاثة علوم علم ظاهر يبذله لأهل الظاهر و علم باطن لا يسعه اظهاره إلا لأهله و علم هو بينه و بين الله تعالى لا يظهره لأحد