What is the ruling if a large volume of water, changed by impurity, loses its change naturally?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
If the water was large and changed by impurity, and the change then disappears on its own, all of it becomes pure.
Supporting text
If the change is removed by adding pure water less than two qullahs, or by the confluence of more impure water, the apparent madhhab is that it remains impure because it cannot repel impurity from itself, and thus cannot repel it from others. However, it is suggested that it becomes pure because the cause of pollution has been removed, just as if it were removed by draining or by remaining stationary.