Umar said to Usama...
Umar said to Usama, ‘Do the messenger of Allah die while you are the emir over me?!’ The Muhajireen denied the homage that the Prophet (S) had taken for Imam Ali (a.s.) in Ghadeer Khum to be the caliph after him. They said, ‘Muhammad thought that this matter (the caliphate) had already been fulfilled for his cousin. How far! It shall not be fulfilled.’[^5] They revealed that in their meetings and so their news reached the Ansar.
They also denied that prophethood and the caliphate would gather in one family. When the Prophet (S) died, Umar announced before people, ‘Prophethood and the caliphate should not gather in one house (family).’ They denied the gathering of prophethood and the caliphate in one house which was the center of the revelation, wisdom and faith. And it was so as they wanted.
The caliphate was extorted from the Ahlul Bayt (a.s.) and turned to be in the hands of the opponents of Islam; the Umayyads and the Abbasids who ruled unlike what Allah willed, and whose palaces were stages for debauchery, drinking, singing, dancing and all sins, whereas the Ahlul-Bayt (a.s.), who were the compare of the Qur'an, were treated cruelly and their heads were raised on the tips of spears, and their women became captives taken from one country to another.
It was this that Quraysh wanted in order to take revenge on the Prophet (S) through his progeny. Second, the Ansar were certain that if the Muhajireen seized power, they would subjugate and oppress the Ansar as revenge. Al-Hubab bin al-Munthir, who was one of the chiefs of the Ansar, declared that by saying, ‘…but we fear that those, whom we had killed their sons, fathers and brothers, may assume it (the caliphate).’[^6] Actually, the prediction of al-Hubab came true.
As soon as the short rule of the four caliphs came to an end, the caliphate was seized by the Umayyads who exaggerated in subjugating and oppressing the Ansar and depriving them of everything to leave them in poverty and wretchedness. Mo’awiya was excessive in revenging on them, and when his son Yazid assumed the caliphate, he spared no effort to offend them. He violated their properties, bloods, and honors in the battle of al-Harrah that history has seldom seen a terrible, cruel event like it.