This is what is termed ṭāhir (pure but not purifying) according to those who hold that water is divided into three categories: ṭahūr (pure and purifying), ṭāhir (pure but not purifying), and impure.

The correct view is that water falls into only two categories: ṭahūr (pure and purifying) and impure. Whatever is altered by an impurity is impure, whereas whatever is not altered by an impurity is ṭahūr. The category of ṭāhir has no basis in the Sacred Law. This was the view preferred by Shaykh al-Islam (1).

The evidence for this is the absence of evidence to the contrary. Had the category of ṭāhir existed in the Sacred Law, it would have been a well-known and clearly understood matter, established by explicit and unambiguous hadiths. This is not a minor matter, for it determines whether one purifies oneself with water or performs tayammum (dry ablution). People need to know it just as they need to know the nullifiers of wudu and similar matters for which there would have been ample reason to transmit reports, had they been established.

Impure water is that which has been altered by an impurity, or which comes into contact with it while being a small quantity, …………..

His statement, “Impure water is that which has been altered by an impurity,” means that its taste, colour, or smell has been altered by the impurity. Excluded from water whose smell has changed is that whose smell changes merely through proximity to a carcass. This ruling is a matter of scholarly consensus: whatever is altered by an impurity is impure. Hadiths have also been narrated concerning this, such as: “Water is pure and purifying; nothing renders it impure” (2).

His statement, “or which comes into contact with it while being a small quantity,” means that it comes into contact with an impurity while containing less than two qullahs. The evidence is the implied meaning of the Prophet’s ﷺ statement: “When water reaches two qullahs, nothing renders it impure” (3).

The implied meaning of his statement, “while being a small quantity,” is that if it comes into contact with it while being a large quantity, then it does not