Here, I will touch on five topics which I hope will shed light on the relationship between Islamic law and the state.
1. Duality of the term "sultan"
In the first centuries of Islam, the term "sultan" sometimes signified "authority" including both administrative and judicial authorities, for in this period these two functions were not clearly distinguished. However, the term came to signify only administrative authority, as distinguished from judicial authority.
2. No state, no application of Islamic law
It is true that the Maliki, the Shafii and the Hanbali jurists unanimously hold that a Muslim is bound by Islamic law, wherever he is. However the Hanafi jurists put a Muslim residing in a Dar al-Harb under no obligation to abide by Islamic law, because he cannot seek any protection by an Islamic court. This is why he is not punished if he commits a crime which would be sanctioned by a hadd punishment if he were in a Muslim territory.
3. Jurists fighting against the state
The fifth Umayyad caliph Abd al-Malik undertook a monetary reform in the A.H.70/690s, as a result of which the weight of a dinar coin was changed from 4,55 g to 4,25 g. But the Umayyads intended for the old coin and the new one to be exchanged equally when their nominal values were equal. The Medinan jurists objected to this policy, which led, together with other factors, to the prohibition of riba (interest).
4. The Qadis' (judges') judgment is binding in his capacity as a mujtahid
Muslim jurists hold that a judgment rendered by a Qadi is accorded the force of law because it is presumed to be a validly constructed approximation of the Law of God. This thesis is intended to safeguard the independence of judicial power from administrative power. Al-Qarafi took up this thesis to defend the Malikis against the domination of the Shafiis under the Mamluk rule in Egypt.
5. The state is sometimes forced to support Islamic law
When Morocco became a protectorate of France, the sultan inserted a clause in the protectorate treaty to the effect that the French should be more reticent when intervening in religious affairs. This clause enabled the sultan to prevent the French from undertaking reform of the chraa court (the ancient qadi court) and altering its jurisdiction, including conflicts over real estate.