You are the son of the most evil one of all Quraysh towards the Apostle of Allah...

You are the son of the most evil one of all Quraysh towards the Apostle of Allah, may Allah bless him and his family, and His Book. Allah alone is sufficient for you. You shall return to Him. You shall know to whom the final result of the abode shall be. By Allah, you shall meet your Lord soon. Then He shall punish you because of what your hands have done. Allah is not unjust for the servants.

"Indeed, when 'Ali passed away (the mercy of Allah be on him on the day when he died, on the day when Allah bestowed Islam on him, and on the day when he will be raised from the dead) the Muslims made me a successor. So I ask Allah not to give us in this transit world a thing with which He decreases our dignity which He has. The thing that made me write to you is an excuse between Allah, the Great and Almighty, and me concerning your affair.

If you do that, you will have great luck, and the Muslims will have righteousness. "Therefore avoid going too far in falsehood, and pledge allegiance to me as the people have done. You know that I am worthier of this authority than you with Allah and with every loyal repentant, and a repenting heart. Fear Allah, abandon oppression, and spare the blood of the Muslims. Enter peace and obedience.

Do not dispute with the people of authority over their authority, and with those who are worthier of it than you. With that Allah will put out this disturbance, unify (the Muslims), and settle the enmity. "If you insist on your error, I will advance against you with the Muslims and punish you till Allah judge between you and me, and He is the best of all judges." [1] In its last words, the letter of al-Hasan, peace be on him, shows you that al-Hasan clearly threatened Mu'awiya with war.

It was necessary for al-Hasan to follow this method. For it was appropriate for Mu'awiya. He asked him "to avoid going on falsehood and to pledge allegiance to him as the people did." This was the wise political method which al-Hasan used to undermine the resistance of the enemy through undermining his determination. Then al-Hasan, peace be on him, said these words to Mu'awiya after telling him about the previous argument of the Prophet's family with Quraysh.

So al-Hasan, peace be on him, summoned Mu'awiya to stop going on falsehood and to pledge allegiance to him. Thus he gave him pieces of advice, then he threatened him, and then he clearly warned him with war. Al-Hasan, peace be on him, followed the plan of his father towards Mu'awiya.