The administrative, governmental implementation of the core religious text or "scripture", the Koran, and Sharia Law (aka just "shari'a" or Muslim Law or Islamic Law) as extracted therefrom.
Siyasa shar’iyya can be described as governance in accordance with the Shari'a or the machinery of an Islamic government, the executive branch of Muslim theocracies (although there is such extensive overlap in theocracies, by definition, that one cannot properly distinguish between an executive branch, a legislative branch and a judicial branch as one can in modern democracies.)
To some practitioners of Islamic Law, Siyasa Shar’iyya refers strictly to the extant regulatory instruments of a Sharia law-based government.
The legal authority for Siyasa Shar’iyya is implied by Muslim theocracies as a necessary extension to their responsibilities to supplement the broad criminal law principles of the Koran and other Muslim legal texts of sacred origin, on points of detail; to make regulations or policy decisions.
Siyasa means politics or in this context, especially policy and is distinguished from the literal content of the Koran, Muslim law, fiqh.
Pearl defines siyasa shar’iyya (sharia) as:
“The right of the executive branch of the (Muslim) government to complete the Sharia by regulations of an administrative kind.”
In their article in the American University International Law Review, the authors offer a description as follows:
"Al-siyasa al-shar'iyya (is) a treatise on the general principles of divine government and appointment to the lieutenancy of the prophet and states that it was indispensable for the ruler and his subjects and for those in charge of affairs....
"Thinkers ... thus proposed that the proper role of shari'a (as interpreted by the jurists) might be best conceptualized as creating an outer boundary on the legislative power of the state.
"Classical legal theory, including the theory of siyasa shar'iyya, had an enormous impact on the political philosophy of the Ottoman state. Justifying its behavior in terms of this theory, the Ottomans imposed as law both unwritten fiqh and, increasingly, statutes, and in part as a result, the empire enjoyed considerable popular legitimacy. The ideal of siyasa shar'iyya came to influence Muslim thought throughout the areas under Ottoman control, including Egypt."
- Lombardi, Clark B. and Brown, Nathan, Do Constitutions Requiring Adherence to Shari'a Threaten Human Rights - How Egypt's Constitutional Court Reconciles Islamic Law with the Liberal Rule of Law, J.21 AUILR 379 (2005-2006)
- Pearl, D., A Textbook on Muslim Law (London: Croom Helm Ltd., 1979), page 20