This, then, shows that what he affirmed is not equal—in ruling or in fact—to what he denied; therefore the two must not be treated alike.

The same principle appears in his ﷺ statement: “No one is to be flogged with more than ten lashes except in a ḥadd, one of the legal punishments set by Allah” (1). Here he distinguished the ḥadd-penalties from all other offences with respect to exceeding ten lashes; accordingly, one may neither draw an analogy between the two nor merge them under a single ruling.

Likewise, he forbade selling fresh dates in exchange for dried dates, yet allowed it in the case of ʿarāyā transactions (2); the two therefore cannot be lumped together, whether to prohibit or to permit them.

He also prohibited ribā al-faḍl (usury of surplus) when the two commodities are of the same kind in the categories he specifically named, while permitting disparity when the kinds differ (3).

The same holds for every other matter in which he differentiated between two things in law.

Accordingly, what the Lawgiver has joined together may not be separated, and what He has separated may not be combined. One of the two approaches must be discarded: either the amalgamation you have presumed—treating as one what the Sharīʿah has kept distinct—or the distinction He Himself has laid down. Because abandoning the latter is impossible, discarding the former is unavoidable.