to pray, since the condition that prevented prayer has ceased.

His statement, “and that which takes its place, and the removal of physical impurity.”

His statement, “and that which takes its place”: the pronoun refers to “lifting,” not to ritual impurity. That is, whatever has the meaning of lifting ritual impurity. In such cases, ritual impurity itself is not lifted, but the act has the same effect or function.

An example is washing the hands after rising from a night’s sleep. This is obligatory and is called purification, yet it does not lift ritual impurity. Thus, if one merely washed his hands, prayer would not be valid. Likewise, if a man renews his ablution—that is, performs ablution while already in a state of ablution—this does not involve the lifting of ritual impurity, even though it is called purification, because it takes the place of lifting ritual impurity.

Similarly, if a person suffering from continuous urinary incontinence performs ablution because of his urine in order to pray, this ablution achieves the functional equivalent of lifting ritual impurity, since the urine has not ceased.

Thus, what is meant by that which takes the place of lifting ritual impurity is every purification that does not itself lift ritual impurity, or that is not performed due to ritual impurity.

His statement, “and the removal of physical impurity”: he did not say, “the act of removing physical impurity.” Thus, the disappearance of physical impurity constitutes purification, whether it disappears on its own or is removed by some other means; in either case, this is called purification.

Physical impurity is filth.

Filth is any tangible substance whose consumption is prohibited—not because of its inviolability, nor because people find it repulsive, nor because it harms the body or the mind. Alternatively, one may say: it is every tangible substance from which one must purify oneself. This is how they defined it (1).