of the leading imams, namely the three: Mālik, al-Shāfiʿī, and Aḥmad.

Their evidence is that the Prophet ﷺ forbade eating the jallalah (an animal that habitually consumes filth) and drinking its milk, because it feeds on impurity.

Shaykh al-Islām Ibn Taymiyyah said: “The correct view is that it is pure once no trace of impurity—neither taste, color, nor odor—remains, for Allah, exalted is He, has permitted the wholesome and forbidden the foul, and this ruling follows the qualities and realities of substances. Therefore, when the substance itself changes into vinegar, it enters the realm of what is wholesome.”

Shaykh Muḥammad ibn Ibrāhīm Āl al-Shaykh stated: “Transformation purifies the impure.”

This is the sound position, and its proofs are clear.

Scholarly disagreement:

The scholars unanimously agree that purifying water removes impurity, but they differed with respect to other liquids and solids that might remove it:

• Abū Ḥanīfah and his companions held that impurity can be cleansed, wherever it is found, by any pure substance that eliminates the physical filth, whether that substance is liquid or solid.

• The three imams maintained that a place cannot be purified from impurity except with purifying water, apart from the specific exemption of istijmār (dry cleansing with stones).

Ibn Rushd said: “The reason for their disagreement is this: Is the objective in removing impurity with water merely to destroy the filth itself—so that anything that destroys it would stand on equal footing with water—or does water possess a further specificity unmatched by anything else?”

Abū Ḥanīfah supported his view with several hadiths and reports, among them what Abū Dāwūd recorded (386) from Abū Hurayrah: the Prophet ﷺ said, “When any one of you steps on filth with his sandals, the earth will cleanse them.”

He also cited what al-Tirmidhī narrated in his Sunan (143) from Umm Salamah, who said to the Prophet ﷺ, “I am a woman whose hem is long and I may walk through a filthy place.” The Messenger of Allah ﷺ replied: