Haroon tried to do something to make the Imam (a.s.) unable and handicapped 
about giving answer to queries and thus devalue and degrade him by this meant. 
But whenever he neared the ocean of Imam's knowledge he found himself 
incapacitated, unable and disgraced.
On one of such occasions Haroon brought Imam (a.s.) from Madina to Baghdad and 
started a discussion.
Haroon: I want to ask you a question about a certain subject, which has remained 
unanswered in my mind.
Imam (a.s.): "If I have the freedom of expression I will answer you."
Haroon: You are free to express yourself.
Imam (a.s.): So say what you feel like?
Haroon: Why do you believe that you are superior to us, the sons of Abbas? 
Whereas, both of us are from the same lineage and (common ancestor) that is to 
say we are all the sons of Hashim.
Imam (a.s.): We are closer to the Prophet (pbuh&hh) than you.
Haroon: How?
Imam (a.s.): Because, our father Abu Talib and the father of the Prophet (pbuh&hh) 
are from the same father and mother. But your father Abbas is related from his 
father's side only.
Haroon: When the Prophet (pbuh&hh) deceased, your father Abu Talib had passed 
away but our father Abbas was living. It is clear that till the time uncle is 
alive you the cousins cannot get the heritage.
Imam (a.s.): Till the time a child is living; the uncle does not get 
heritage. Therefore, when Fatima Zahra (sa.) is living your father Abbas cannot 
gain the heritage.
Haroon: Why do you allow people to call you the son of Prophet (pbuh&hh) 
whereas, you are the sons of Imam Ali (a.s.). Because everybody is related to 
his father and Prophet (pbuh&hh) is your maternal grandfather.
Imam (a.s.): If the Prophet (pbuh&hh) becomes alive and asks you the hand of 
your daughter in marriage, are you prepared to give her hand to him?
Haroon: With great and utmost honor.
Imam (a.s.): But the Prophet (pbuh&hh) will never ask me the hand of my 
daughter in marriage.
Haroon: Why?
Imam (a.s.): Because, he is my father although from mother side but he is not 
your father. Therefore, I can consider myself the son of the Prophet (pbuh&hh).
Haroon got silent, calm and cool by the crushing answers of Imam (as) and he 
asked Imam (a.s.) to demand anything from him. Imam (a.s.) said, "I do not 
want anything from you, just let me go free to do my work."

