then a large quantity of water, in the terminology of the jurists, is that which reaches two qullahs, while a small quantity is that which is less than two qullahs.

They are approximately five hundred Iraqi ratls. If an impurity other than human urine or liquid human excrement mixes with it but does not alter it, …

His statement, “They are approximately five hundred Iraqi ratls”: one hundred Iraqi ratls weighs approximately one waterskin of water. Thus, they amount to approximately five waterskins. By saying, “approximately,” the author indicates that the matter is not one of exact specification; hence, a slight deficiency does no harm.

His statement, “If an impurity mixes with it,” means: if it becomes intermixed with it. The definition of impurity has already been mentioned. (2)

His statement, “other than human urine or liquid human excrement, but does not alter it”: what is meant is that it does not alter its taste, colour, or smell. This issue—namely, when an impurity mixes with water—has three views: (3)

The first view—the established position of the earlier scholars of the madhhab—is that if an impurity mixes with water that is less than two qullahs, it becomes impure in all cases, whether it changes or not, and whether the impurity is human urine, liquid human excrement, or something else. But if it reaches two qullahs, a distinction is made between human urine and liquid human excrement on the one hand, and all other impurities on the other. Thus, if it reaches two qullahs and human urine or its excrement mixes with it,