What is the ruling when the combined volume of converging streams is less than two qullahs, and some are impure?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
If the collective volume is less than two qullahs, and some streams are impure, according to the apparent madhhab, all of it is impure. If the volume is two qullahs, but all streams are impure, or some are pure and some impure such that the pure portions do not connect continuously to reach two qullahs, the apparent madhhab is that all is impure, even if extensive.
Supporting text
There is a possibility that it is considered pure, which is the position of Al-Shafi'i, based on the hadith: 'When water reaches two qullahs, it does not carry filth,' and because it is a large volume of water not changed by impurity, it should be pure, as if the change had been removed by sitting or flowing. Our proof is that the impure has joined the impure, making all impure, just like in matters other than water. Even if some part is pure, if it is little, it cannot repel impurity from itself, let alone from others.