And the meaning of his statement, "and between them are ambiguous matters," is that they are ambiguous to some people and not to others—not that they are in themselves ambiguous with no clarification for them within the overall foundations of the Sacred Law. For Allah, exalted is He, has not left any matter for which a ruling is required without having placed in it clarification and established upon it a proof. Rather, clarification is of two kinds: a clear clarification, known to the general masses of people alike, and a subtle clarification, known only to the elite among the scholars who have devoted themselves to the science of legal principles, thereby deriving the meanings of the texts, learning the method of analogy and deduction, and referring matters to their like and equivalent. The proof of the soundness of what we have said—and that these matters are not in themselves ambiguous—is His statement: "which many people do not know." For by understanding the import of this, it is understood that some people do know them, even if they are few in number. So when they are known to some of them, they are not ambiguous in themselves. Rather, what is incumbent upon the one to whom they are ambiguous is to pause, to clear himself of doubt, and not to proceed except upon clear insight. For if he proceeds upon a matter before verification and discernment, he is not safe from falling into what is forbidden to him—and that is the meaning of the protected pasture, to which he drew an analogy.

And his statement, "the lawful is clear and the unlawful is clear," is a great principle in many matters and rulings when ambiguity arises in them or doubt occurs regarding them. Whenever that is the case, the obligation is to examine: if the matter has a basis in prohibition or permissibility, one adheres to it and does not abandon it due to the objection of doubt until certainty of knowledge removes it. An example of the lawful: a wife whom a man has, or a slave-girl in his possession whom he takes as a concubine and has intercourse with, and he doubts whether he divorced the former or freed the latter—both remain with him on the basis of permissibility until the occurrence of divorce or emancipation is confirmed. Likewise, water in his possession whose basis is purity—he doubts whether impurity has fallen into it or not—it remains on the basis of purity until he is certain that impurity has affected it. And like a man who performs ablution for prayer and then doubts concerning an event of impurity—he prays as long as he does not know with certainty that an impurity occurred. And upon this example [the principle proceeds].

As for a matter whose basis is prohibition, and it is only rendered permissible upon known conditions and specified forms—such as private parts, which are not lawful except after marriage or possession by right of ownership, and such as a sheep whose meat is not lawful except by proper slaughter—then whenever one doubts the occurrence of those conditions and their attainment with certainty in the manner made the sign of permissibility, it remains upon the basis of prohibition and unlawfulness. And upon this example: if a man's wife were mixed with unrelated women, or properly slaughtered meat were mixed with carrion, and he could not distinguish them by their specific identity, it would be incumbent upon him to avoid them all and not approach them. And these two categories have the ruling of obligation and necessity.