to the mosque, let him examine his sandals. If there is any filth on them, let him rub them against the earth, for earth purifies them.” Since earth has thus been made a means of purifying the underside of a leather sock, it is all the more fitting that earth itself should become pure.
Moreover, it is well known that most paths people use are liable to contain as much impurity as graveyards, bathhouses, and similar places, or even more. If that were the reason for the prohibition, he would have forbidden prayer in sandals altogether, since the possibility of impurity is more evident in their case.
These teachings of the Sunnah therefore invalidate that explanation on two grounds: this possibility was disregarded, and earth purifies what it ordinarily comes into contact with.
Our purpose here, however, is to discuss the water running through a bathhouse. We therefore say: finding this water objectionable, avoiding it, and washing off whatever reaches the body or clothing may be based either on considering it dirty or on considering it ritually impure. The former is like washing one’s body and clothing to remove dirt and grime, mud that gets on them, nasal mucus, spittle, semen—according to the view that it is ritually pure—and similar things. The same may apply to water whose properties have changed because of where it collects, substances mixed with it, or similar causes. This is a different matter from the one we are discussing now.