The advocates of the penalty of death for apostacy also rely in support of their thesis on the case of Musailamah Kazzab. They pose the question: If there is no penalty for apostacy, why was Musailamah Kazzab not left alone and why was he fought against? The reply is that if he had confined himself to his claim of prophethood and had not entered into any political activity in opposition to the Muslim state, there would have been something which those who differ with us could have relied upon. But the facts refute them. The object of the activities of Musailamah Kazzab was to obtain political power and his false claim of prophethood was only a means towards that end. During the lifetime of the Holy Prophet, peace be on him, he had come to Medina with a delegation of Banu Haneefah and had proposed to the Holy Prophet that he would submit to him in case he was nominated the successor of the Holy Prophet. He was told by the Holy Prophet that he would not yield him even a twig of a date palm tree. When he went back he claimed to be a prophet and announced that half the country belonged to him and half belonged to the Quraish. He sent the following letter to the Holy Prophet: From Musailamah, Messenger of Allah, to Muhammad, Messenger of Allah. Peace be on you. I have been appointed your partner in authority. Half the country belongs to us and half belongs to the Quraish, but the Quraish are a people who transgress (Tabari, V 01. IV, p.1849).
The Holy Prophet replied to him: The earth belongs to Allah; He bestows it as heritage on whomsoever He pleases of His servants, and the pleasing end is that of the righteous (7:129). Thereafter, Musailamah established his authority in Hajar and Yamamah and expelled therefrom the functionaries who had been appointed by the Holy Prophet (Khamees, Vol.II, p.177). He made a junction with Sajah, the female rebel, who had intended to fight the Muslims and assured her: I shall establish my authority over the whole of Arabia with the help of my people and thy people (Tabari, Vol. IV, p.1918). After his claim of prophethood, he encountered Habeeb bin Zaid and Abdullah bin Wahb Aslami, two of the Companions of the Holy Prophet, and having captured them, he asked them to acknowledge his prophethood. Abdullah yielded to his persuasion and became an apostate, but Habeeb stoutly resisted and Musailamah had him cut up limb by limb and then burned him (Khamees, Vol. II, p.641).
In the face of all this, can the advocates of the penalty of death for apostacy still contend that Musailamah was fought only on account of his apostacy and that his case lends any support to the thesis that simple apostacy is punishable with death? Musailamah had become so strong that when he fought Khalid bin Waleed in Yamamah, he had under his command 40,000 warriors of the Banu Haneefah alone. The fighting was so severe as the Muslims had not experienced before. Yet those who differ with us represent Musailamah as a harmless apostate and contend that if simple apostacy was not punishable, he should have been left alone.