By their nature...
By their nature, in fact, laws and social institutions require the existence of an executor. It has always and everywhere been the case that legislation alone has little benefit: legislation by itself cannot assure the well-being of mankind. After the establishment of legislation, an executive power must come into being, a power that implements the laws and the verdicts given by the courts, thus allowing people to benefit from the laws and the just sentences the courts deliver.
Islam has therefore established an executive power in the same way that it has brought laws into being. The person who holds this executive power is known as the Waliul Amr .[^2] The sunnah [^3] and path of the Prophet (SAWW) constitute a proof of the necessity for establishing government. First, he himself established a government, as history testifies. He engaged in the implementation of laws, the establishment of the ordinances of Islam, and the administration of society.
He sent out governors to different regions; both sat in judgment himself and also appointed judges; dispatched emissaries to foreign states, tribal chieftains, and kings; concluded treaties and pacts; and took command in battle. In short, he fulfilled all the functions of government. Second, he designated a ruler to succeed him, in accordance with Divine command.
If Allah Almighty, through the Prophet (SAWW), designated a man who was to rule over Muslim society after him, this is in itself an indication that government remains a necessity after the departure of the Prophet from this world. Again, since the most Noble Messenger (SAWW) promulgated the divine command through his act of appointing a successor, he also, implicitly stated the necessity for establishing a government.
It is self-evident that the necessity for enactment of the law, which necessitated the formation of a government by the Prophet (SAWW), was confined or restricted to his time, but continues after his departure from this world.
According to one of the noble verses of the Qur`an, the ordinances of Islam are not limited with respect to time or place; they are permanent and must be enacted until the end of time.[^4] They were not revealed merely for the time of the Prophet (SAWW), only to be abandoned thereafter, with retribution and the penal code no longer be enacted, or the taxes prescribed by Islam no longer collected, and the defense of the lands and people of Islam suspended.