Imam Hasan (A.S.) Answers

Muawiya sent a disguised man to Kufah to ask Amirul Muminin Ali (A.S.) for the answers of certain questions that the King of the Romans addressed at him. The Imam could recognize the man who confessed of his reality as soon as he was interrogated.

Amirul Muminin(A.S.) said, "Allah may curse son of that who ate the livers(Hinda,Muawiya's mother). He, as well as his followers, is extremely deviant. Allah curse him. He manumitted a bondmaid. It was preferable for him to marry her. May Allah be the judge between this nation and me. They disregarded my kinship, discounted my great rank, and wasted my characters. "

He then summoned Al-Hasan, Al-Husayn, and Muhammad bin Al-Hanafiya. As they were before him, the Imam Ali(A.S.) said, "O Syrian brother, these two are the Prophet's sons and this one is mine. You may ask anyone of them."
The man referred to Imam Hasan (A.S.), then put his questions:
"What is the distance between the right and the wrong?
What is the distance between the heavens and the earth?
What is the distance between the east and the west?
What is that colorless spot seen in the moon?
What is the rainbow?
What is this galaxy?
What was the first thing that sprinkled on the earth?
What was the first thing that shook on the earth?
What is the spring at which all the spirits of the believers and the disbelievers lodge?
What are the ten things one of which is stronger than the other?"

Imam Hasan (A.S.) answered:
O Syrian brother, what is between the right and the wrong is only the distance of four fingers. The right is only what is seen with the eye, whereas you may hear very much wrong with the ears.
What lies between the heavens and the earth are the supplication of the wronged man and the extension of the sight. He whoever says anything else is lying.
What lies between the east and the west is a day with steady movement of the sun. You wait for sunrise and then wait for sunset. He whoever says anything else is lying.
This galaxy is the rips of the heavens and the place from which the torrential water ascended to Noah the Prophet (A.S.).
Regarding the rainbow, you should not name it 'Quzah ---the bow of Quzah-' because 'Quzah' is the name of a devil. You should name it 'Qawsullah---the bow of Allah-'. It is security against drowning.
Regarding the colorful spots of the moon, the moonlight was as shiny as sunlight, but Allah erased it. This is His saying: We have made the sign of the night to pass a way and We have made the sign of the day manifest. (Holy Qur'an 17:12).
The first thing that sprinkled on the earth was valley of gloom.
The first thing that shook on the earth was date-palm tree.
The spring at which the spirits of the believers lodge is a spring named Salam.
The spring at which the spirits of the disbelievers lodge is called Barahout. 
The strongest creation of Allah was the stone. Iron is stronger than the stone. Fire is stronger than iron. Water is stronger than fire. Clouds are stronger than water. Wind is stronger than clouds. The angels are stronger than wind. The angel of death is stronger than the other angels. Death is stronger than the angel of death. Allah's act is stronger than death.
The Syrian man said: I declare that you are surely the son of the Prophet (S.A.W.) and I declare that Ali (A.S.) is surely Muhammad's successor."
He then wrote down the answers and took them to Muawiya who sent them to the king of the Romans. As the latter received them, he said, "I am sure this is not Muawiya's. These are surely the answers from the House of Prophethood.
 

About the Source of Power
Hasan al-Basri wrote the following missive to Imam Hasan ibn Ali(A.S.):
So then, you, the Hashemites, are the progressing ships in the high waves, the celebrated illuminative signs, and the ark of Noah(A.S.) on which the believers embark and by which the Muslims are saved. I write to you, son of the Prophet, about our argument about fate and our perplexity about the source of power. I wish you would tell us of the opinion of your fathers and yours. It is surely that your knowledge is a part of Allah's, and you are the witnesses on people and Allah is the witness on you. You are the offspring of one another, and Allah is All-hearing and All-seeing.
Imam Hasan(A.S.) answered:
In the Name of Allah, the Beneficent, the Merciful.
I have received your missive. Only because you referred to the perplexity of you and those who passed, I will explain the question to you.
He who does not believe in the fact that Allah has full acqaintance with the good and the evil of the fate is disbeliever.
He who refers the doing of the acts of disobedience to Him is sinful.
Allah has not been obeyed by force and has not been defied due to His being overcome. He has not respited the servants uselessly. He is surely the possessor of what He has given to them in possession and controls what He has empowered. His commandments are obligatory and His warnings are means of caution.
If the servants cling to the obedience to Allah, they will not find any barrier in their way and if they disobey, Allah may do them favor by precluding them from doing such acts of disobedience. If He does not do, then it is not He who encourages them committing so by force or compulsorily. On the contrary, He does them the favor of informing, advising, warning, ordering them not to do so.
He does not frame them to obey Him like the angels and does not oblige them to commit acts of disobedience to Him.
Final authority belongs only to Allah. Had He wanted, He would have given you all guidance. Peace be upon those who follow the right guidance.
 

His Sermon when Muawiya said "Refer to our merits." after Signing the Peace Treaty
All praise and thanks belong to Allah. Peace be upon Muhammad(S.A.W.) the Prophet and his family.
This is I for those who know me. For those who do not know me, I say that I am Al-Hasan, the son of the Messenger of Allah(S.A.W.). I am the son of the proclaimer of the good tidings and the warner. I am the son of the chosen for the Divine Message. I am the son of that whom the angels have blessed. I am the son of that by whom the umma have been honored. I am the son of that to whom Gabriel the angel was the emissary of Allah. I am the son of that whom was sent as mercy for the peoples. All peace and blessings be upon him and his family.
As Muawiya could not control his malice and envy, he said to the Imam(A.S.), "O Hasan, describe ripe dates for us."
Imam al-Hasan(A.S.) said: Yes, Muawiya, I will do. Ripe dates are pollinated by the wind, puffed by the sun, colored by the moon, ripened by hot weather, and cooled by night.
Imam al-Hasan(A.S.) then was back to continue his sermon: I am the son of that whose supplication is answered. I am the son of that who was as close to his Lord as the distance of two bows, or even less. I am the son of the obeyed interceder. I am the son of Makkah and Mina. I am the son of that to whom the people of Quraish submitted unwillingly. I am the son of that whose follower will be happy and whose disappointer will be unhappy. I am the son of that to whom the earth has been made a place of prostration and pure. I am the son of that to whom the news of the heavens came successively. I am the son of those from whom Allah has kept filth away and purified them thoroughly.
Muawiya said: O Hasan(A.S.), I think you are willing for the position of caliphate!"
Imam al-Hasan(A.S.) answered: Woe to you, Muawiya. The true caliph is that who pursues the practices of the Messenger of Allah(S.A.W.) and acts upon the obedience to Allah. I swear by my life, we are surely the signs of guidance and the light marks of God-fearing. You, Muawiya, are one of those who extinguished the (prophetic) traditions, livened up heresies, betook Allah's
servants as slaves and Allah's wealth as means of play.Hence,He caused your affairs to be obscure and you will live for a short time and burden the consequences of your evildoings. O Muawiya, Allah has created two cities: one in the east and the other in the west. He named them Jabulqa and Jabulsa. Except my grandfather the Prophet(S.A.W.), Allah has never sent anyone to these cities.