any kind may be removed and they may be clean at all times. That health and cleanliness are two of the great purposes which wudzū’ serves, in addition to its spiritual meaning, is shown by the stress which is laid on rinsing the mouth with the aid of a tooth-brush (miswāk).
Clean mouth and teeth not only improve the general cleanliness of the body but also exclude a large number of diseases. The Holy Prophet thought so highly of the tooth-brush that he never neglected it under any condition; even on his death-bed he asked for a tooth-brush, and expired only a few minutes afterwards (Bu. 64:85). It was his custom to arise for the Tahajjud prayer soon after midnight, and even at that hour he used first to clean his mouth and teeth with a tooth-brush (Bu. 4:73; M. 2:13). He attached such importance to the cleansing of the mouth that he used repeatedly to say that the only thing which prevented him from declaring the use of the tooth-brush obligatory at every prayer (i.e., at least five times daily) was the fear that it might be a burden on his community (Bu. 11:8; 30:27). On another occasion he is reported to have said that the tooth-brush cleans the mouth and brings about the pleasure of God (mardzāt-un li-l-Rabb) (Bu. 30:27). Similarly gargling is recommended to keep the throat clean, which is also beneficial to health.
The taking of a bath is rendered necessary in certain cases.22 It should be noted in this connection that it is a mistake to call the state in which a man is under an obligation to perform a wudzū’ or take a bath, a state of defilement. It is simply a first step towards going to prayer, and undoubtedly promotes habits of cleanliness and is conducive to health. The direction is contained in the Holy Qur’ān itself: “And if you are under an obligation to perform a total ablution (Junub), then wash yourselves” (5:6). Bathing is also enjoined in Ḥadīth on occasions of large gatherings, such as the Friday prayers and the ‘Īd prayers, when clean clothes must also be put on and scent used if available. These directions have thus both a religious and a hygienic value. They serve as a kind of preparation for going before a higher Presence, and help to wrest the attention of man from lower objects
22 These cases are:(1) pallutio nocturna or iḥtilām, (2) coitus or sexual intercourse; and in the case of women especially, (3) menses or ḥaidz and (4) puerperium or nifās. During the period of menses and puerperium a woman is exempted from prayer. Menstruation generally lasts from three to ten days, and a bath should be taken, when the flow stops, after a minimum period of three days, the maximum limit being ten days, after which bath should be necessarily taken. In the first two conditions a man is called junub, from janb meaning a side. To call this a state of pollution or defilement is not correct, and no lexicologist supports it. On a certain occasion when one such person, a junub, described himself as najs (polluted or defiled) in the presence of the Holy Prophet, he corrected him by saying that a Muslim does not become defiled (Bu. 5:23). It is a technical term and means one who is under an obligation to perform a total ablution or bathing (LL.). The connection with the root-meaning is that such a person is on a side or remote from prayer (R.).