The duty to obey juristic injunctions in Islamic law is often assumed to follow a simple model: God commands, the jurists discover the meaning of those commands, and the faithful follow the jurists’ interpretation. By examining the arguments advanced by some prominent classical Islamic jurisprudes in support of the claims for law's normativity, I show that the jurists saw themselves as representatives of their communities in the quest to formulate opinions about actions in a way that is faithful to revelation. This model can be summarized as follows: (1) the jurists, by virtue of their knowledge, inform individuals of how to act according to revelation; (2) the pronouncement of a jurist who is knowledgeable and fair may be followed without revisiting their justifications; (3) everyone has a duty to act according to revelation and to rebuke those who do not. A reasonable individual should be motivated to follow juristic pronouncements when all these conditions are present. My main claim is that the basic model wherein God is an authoritative commander and the jurists are informants is unsatisfactory. The jurists saw themselves as more than mere discoverers and informers. This Islamic model has unique features when it comes to understanding authority in general. The uniform commitment to a formal moral source, coupled with the contingent nature of the robust reasons given by the system, make the Islamic model distinct from some modern accounts. The Islamic model offers a view of legal authority that is specific to a cohesive community that shares a basic moral commitment. This model fits the classical need for a theory of authority that is both persuasive and authoritative.