The second opinion is that it is purified, due to his saying, peace and blessings of Allah be upon him: "Any hide that is tanned is thereby purified." It is also because it was purified by its transformation, so it does not require the use of water, like wine when it turns into vinegar.

The first opinion is preferable. The report and the meaning both indicate the purity of its substance; this does not preclude the necessity of washing it from an impurity it encounters, just as if it were touched by an impurity other than the tanning agent, or if it were touched by the tanning agent after it had been separated from it.

Section: Tanning does not require an intentional act (fi'l), because it is a removal of impurity, thus it resembles the washing of land. So, if the skin of a dead animal fell into a tanning pit without an intentional act and became tanned, it would be purified, just as if rainwater fell on impure ground, it would purify it.

Section: If an animal whose meat is not eaten is slaughtered, its skin is impure. This is the opinion of al-Shafi'i.

Abu Hanifa and Malik said: It becomes pure, due to the saying of the Prophet, peace and blessings of Allah be upon him: "The tanning of the hide is its dhabh (slaughter)," meaning: it is like its slaughter. He compared tanning to slaughter, and that which is compared is stronger than that to which it is compared. If tanning purifies despite its relative weakness, then slaughter is more appropriate. Also, because tanning removes the 'illah (effective cause of impurity) after it has come into existence, while slaughter prevents it, and prevention is stronger than removal.

Our argument is that the Prophet, peace and blessings of Allah be upon him, forbade sitting on the skins of predators and riding on leopard skins, and this is general for both that which is slaughtered according to Islamic law and that which is not. Also, because it is a slaughter that does not purify the meat, so it does not purify the skin, like the slaughter of a Magian or a non-legitimate slaughter; it resembles the original state. As for the report, we have already responded to it previously. Furthermore, we say: Tanning only has an effect on the animal whose meat is eaten, and so it is the same for that which it was compared to. Even if we conceded that it has an effect in purifying others, it does not necessarily follow that purification is achieved through slaughter, because tanning removes the filth and all moisture, rendering the skin sound in a way that prepares it for preservation such that it does not change, whereas slaughter does not achieve this; therefore, it cannot dispense with the need for tanning.

Their statement that "that which is compared is weaker than that to which it is compared" is not binding, for Allah Almighty said in the description of the Houris: "As if they were hidden pearls" (32), and they are more beautiful than pearls. A beautiful woman is compared to a gazelle and a wild cow, yet she is more beautiful than both. Their statement that "tanning removes the 'illah"...