For the Muslims unanimously agree that when Allah begins to break wine down and turn it into vinegar, it becomes pure. The same applies to transformations involving animals and trees. Indeed, I would go further:

An examination of the various cases shows us that whenever Allah begins to transform and change something from one kind into another—as when He turns wine into vinegar, blood into semen, a clinging clot into a lump of flesh, or the foul flesh of animals that feed on filth into wholesome flesh—the ruling of impurity ceases to apply. The same holds for their eggs and milk, and for crops irrigated with impure water when they are subsequently irrigated with pure water, and other such cases. The impure substance no longer exists as such, nor does the designation corresponding to its nature. This is self-evident and cannot be disputed. Allah transforms all created bodies on earth from one state into another, giving them one form after another, without regard to their original materials and constituent elements.

As for transformation brought about by human action, such as burning dung until it becomes ash or placing a pig in a salt bed until it becomes salt, there is a well-known disagreement concerning it. The view that such transformation renders a substance pure has clear and reasonable grounds. Our present question, however, belongs to the first category, and all praise belongs to Allah.

The fifth argument:

Semen differs from everything else discharged from the penis in its consistency: it is thick, whereas those other fluids are thin. It also differs in colour, being intensely white, and in smell, being pleasant like the scent of date-palm blossoms, whereas the others smell foul.

Moreover, Allah made it the origin of all His prophets, His allies, His righteous servants, and the human being whom He has honoured. How, then, could the human being’s origin be impure? This is why Ibn ‘Aqīl—who had debated someone who maintained that it was impure—said