Moreover...
Moreover, he made use of the Kufans attitude towards him so that he was in no need of any other experience. Al-Hasan's final answer to his companions was: "Every man of you should sit in his house as long as Mu'awiya is living. If Mu'awiya perished and you and I were alive, we would ask Allah for a decision to guide us, to help us in our matter, and not to leave us alone. Indeed Allah is with those who fear (Him) and who do good deeds." [2] 2.
Fulfilling the second Stipulation The neutral and the partial historians have unanimously agreed on that the condition which Mu'awiya gave to al-Hasan within the conditions of the Peace Treaty was that the former should not hand over the authority to anyone after him. This means that he had to hand [1] Ibn Qutayba al-Dinawari, al-Imama wa al-Siyasa, vol. 1, p. 151. [2] Ibid, p. 152. it over to its legal owner, namely al-Hasan b. 'Ali.
If al-Hasan died, the authority had to be handed over to his brother al-Husayn according to the condition that said that handing over the authority to Mu'awiya was limited to his lifetime, and that he had no right to hand it over to anyone after him. Also the historians have unanimously agreed on that Mu'awiya violated this condition openly and appointed his son Yazid as a successor after him. Now, we do not intend to discuss with Mu'awiya about the stipulation which he made, and then violated.
However, he added this error to his errors which the Peace Treaty indicated whether he knew that or not. We have discussed the attitude of Mu'awiya towards his promises several times, so there is no need to discuss the most dangerous error which Mu'awiya made when he appointed his son Yazid as a successor after him. In this connection we say: Through this ugly act, Mu'awiya committed the gravest sin in his religion, and the most horrible crime towards the public interest.
Because of this impudent improvised act of Mu'awiya, the leadership of Islam deviated from its righteous way, the subjects lost their practical example, selfishness prevailed that society, the individuals and the groups mistreated each other, and the relationship between the leaders and their followers ended. Accordingly, the people's inclinations became various and their aims became different.
Besides the Umayyad authority was leading them to corruption so that they got ready to declare their bloody revolts and their internal uprising that were necessary to correct the errors and to warn the others against the dangers.