Others say: “Water is flowing while it removes impurity, and flowing water does not become impure unless its properties change.” This is the position of Abū Hanīfa and Mālik, the more explicit of the two positions reported from Ahmad, and al-Shāfiʿī’s earlier view. Yet impurity is sometimes removed by flowing water and sometimes without it flowing, as when water is poured onto a garment in a basin.

The correct view, therefore, is that legal analogy requires that water not become impure unless its properties change. Impurity cannot be removed with it unless it is free of such change. While its properties remain altered, the water is impure, though it can reduce the impurity. Its removal, however, is achieved only with water whose properties are unaltered.

The same reasoning that applies to water applies to all liquids: they do not become impure if the impurity has undergone transformation within them and no trace of it remains, for they are then wholesome things, not foul things. This reasoning applies equally to small and large quantities of water, and to small and large quantities of other liquids. If evidence from the revealed law establishes that any such liquid is impure, we do not say that this contradicts legal analogy. Rather, we say that this indicates that the impurity has not undergone transformation.

For this reason, the strongest view concerning water is that of the scholars of Medina and Basra: it does not become impure unless its properties change. This is one of the positions reported from Imam Ahmad, supported by a group of his followers, including Imam Abū al-Wafā’ ibn ʿAqīl and Abū Muhammad ibn al-Manī.