What is the ruling when unconnected portions of water, one changed and one unchanged, are present, both under two qullahs?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
If the impure part of the still water borders the flowing water, and the unchanged portion is not connected above, below, or to the sides, then all of it should be considered impure because any contact with the impure water does not reach the two-qullah threshold.
Supporting text
If the connection occurs from one side, whatever remains unchanged is pure if it reaches two qullahs, analogous to two ponds connected by a small channel. If there is doubt, the water is pure because the default state is purity, and doubt does not negate certainty.