Tracing the genealogy of constitutionalism, Mads Qvortrup, in his book ‘The Political Philosophy of Jean-Jacques Rousseau’, writes that “the law given to Moses by the Lord was the birth of constitutionalism….The power of the king, or ruler, was restricted by a higher law….Unlike their contemporary colleagues in Babylon or Egypt, the Jewish kings were restricted in their action by the law as laid down by God….The king’s role was to apply the law – he was a judge rather than a law-giver….Political theorists and practitioners, until Marsilius of Padua, held it undisputed that the law was given by God… and that the ruler could not, and should not, change the law but merely apply it…The work of Marsilius of Padua in the fourteenth century was a turning point. [Marsilius was of the view that] The ruler should legislate – not merely adjudicate.”
The Quran also makes it clear that the Jews were judged and ruled by the Prophets (a.s.) of their times according to the Divine Book revealed to them by the Almighty. Similarly, the Christians were also judged and ruled by the Jesus Christ (a.s.) according the Gospel revealed to him by God. Similarly the last Prophet/Messenger of God, Muhammad (s.a.w.) was also commanded by God to judge or rule people according to the Divine Book revealed to him, comprising the latest and the last edition of the Divine laws. The Quran clearly emphasizes on establishing the rule of the (Divine) law and makes it clear that any who do not judge and rule according to the Book revealed by God, are disbelievers (kaafiroon), wrong-doers (zalimoon) and rebels or deviators from the right path (fasiqoon). The rule of Divine law is thus the foundation of the Islamic Political System.