must be believed. We may not believe in part of the Book and disbelieve in another part. Nor is attending to his intended meaning in one text rather than the other any more justified than the reverse. If he believes that he has followed the Messenger’s intent in the text that agrees with his position, he must do likewise with the other text that he has interpreted. His primary aim must therefore be to ascertain what the Messenger intended by his words. This is the purpose of all permissible tafsīr (explanation) and ta’wīl (interpretation), according to those whose terminology distinguishes their meanings. As for those who regard them as synonymous—as is generally the usage of Quran commentators—ta’wīl means tafsīr. But “ta’wīl” in the words of Allah and His Messenger has a third meaning, distinct both from its meaning in the terminology of Quran commentators and from its meaning among later jurists and scholars of legal theory, as explained at length elsewhere.

The point here is that whenever Allah and His Messenger deny the applicability of a designation for obligatory matters—such as faith, Islam, religion, prayer, fasting, purification, Hajj, and so forth—it is only because an obligatory element encompassed by that designation has been omitted. An example is His saying, Most High:

“But no, by your Lord, they will not believe until they make you judge in their disputes, then find within themselves no discomfort at what you have decided and submit completely.”

Since He negated faith until this condition is fulfilled, this indicates that fulfilling it is obligatory upon people. Whoever neglects it is among those subject to the threat of punishment: he has not fulfilled the obligatory faith whose possessors have been promised entry into Paradise without punishment. Allah has promised this only to those who do what they have been commanded. As for someone who performs some obligations and neglects others, he is exposed to the threat of punishment.

It is established by the consensus of the Muslims that it is obligatory to “make the Messenger the judge” in every dispute between