Abū Hanīfah, the Zāhirīs, and others—the matter is clearer still according to their view, for they say:

Impure dung becomes pure if it turns into ash or the like. Likewise, blood, carrion, and similar substances that fall into a saltworks become pure if they turn into salt. They all agree that wine becomes pure when Allah, glorified is He, causes it to turn into vinegar. This is also established from ʿUmar ibn al-Khattāb and other Companions. They therefore judge other substances that undergo transformation by analogy with wine that has been transformed.

Those who distinguish between the two cases justify this by saying that wine became impure through transformation and thus becomes pure through transformation: the juice was pure, then became impure when it turned into wine, and becomes pure when it turns into vinegar. This is a weak argument, for all impure substances likewise became impure through transformation. An animal, while alive, consumes pure food and drink; then it dies and becomes impure. Likewise, pigs, dogs, and beasts of prey—according to those who consider them impure—were created from pure water and earth.

Moreover, this vinegar, salt, and similar things are wholesome, pure substances included in the words of Allah Most High:

“He makes lawful for them what is wholesome and forbids them what is foul.”

Someone who declares these substances forbidden and impure may say that he prohibits them because they are either expressly covered by the revealed text or fall within its meaning. Yet neither is the case, for the text does not cover them