The Qur'an assigns rulership not only to the Prophet of...
The Qur'an assigns rulership not only to the Prophet of Islam but also to Yusuf (Joseph): When Yusuf reached maturity We bestowed on him rulers hip and knowledge; thus do We reward the doers of good." (12:22) The Qur'an addresses Dawud (David) as follows: "O Dawud We bestowed upon you Our viceregency upon earth so that you might rule justly among God's creation not following your vain desires for they would lead you astray from God's path." (38:25) The Islamic laws concerning fixed penalties and the payment of blood money as well as many other topics in jurisprudence count as the executive pillars of the Islamic system of government that was founded by the Prophet.
The governmental function of the Prophet had another important dimension that of creating a suitable environment for the strengthening of the Islamic summons expounding the divine laws and ordinances for mankind and inculcating in men the concepts of God's Book so that they might attain the lofty goals that Islam had prescribed.
( 138 ) The Qur'an says the following with respect to this aspect of the Prophet's task: "God it is Who raised a great Prophet from among the unlettered Arabs in order that he might recite to them the verses of God's revelation and cleanse them from tire pollution of ignorance and evil morals and teach them tire shari'ah of God's Book and divine wisdom even though they were previously in tire pit of ignorance and misguidance." (62:2) The Prophet was thus the ruler of Islamic society in addition to being a guide and a promulgator of God's ordinances.
Whoever wished to be his successor ought then to have combined in himself these same two dimensions - rulership of society and the spiritual guidance of the ummah. In addition he had to be the guardian of the credal based of Islam and its ordinances protecting them from change or distortion and resisting decisively the assaults of unbelief scepticism and misguidance; one able to solve problems arising from any kind of deviation and to confront any agggression of the Islamic lands by outsiders.
Only thus could the continuity and preservation of Islam be assured amid the myriad dangers it faced. The best method of preserving the rights of the individual and society is to have a government of the righteous and the most righteous form of government is without doubt the government of the inerrant (ma'sum) which alone makes it possible to hope for the preservation of the rights of all man.