Chapter: The legal status of water—what renders it impure and what nullifies its purifying capacity

Water is of two kinds: running and still.

1. Running water: If an impurity falls into running water, the current carries it away, and everything downstream of the point of contact remains pure.

2. Still water: When originally pure, it is further divided into two categories:
   a) Water that is intrinsically pure and purifying—one may perform wuḍūʾ with it and wash away filth.
   b) Water that is pure in itself and lawful to drink, yet it may not be used for ritual purification or for removing impurity; it is pure but not purifying.

The first type—that which is both pure and purifying—is plain, clear water: rainwater, water from rivers, seas, springs, wells, and anything people simply call “water,” unaffected by admixture, just as Allah created it, clear and unspoiled by the natural color of the river-bed or soil.

The second type—pure yet unsuitable for purification—is water to which a pure substance has been added and mixed so thoroughly, or extracted in such a way, that the substance changes its very name, color, taste, or smell. Examples include water in which bread has been soaked, or in which figs, oil, dates, or a hide have been left; water that has come into contact with saffron, oil, rosewater, plant juice, and the like—anything that predominates and alters its taste, color, or odor. Once this occurs, the use of such water for ritual purification becomes prohibited.