The Sunan Al-Fitrah which were enjoined by the Prophet, peace and blessings of Allah be upon him, represent the basis of individual cleanliness. Imam Muslim narrated that the Messenger of Allah, peace and blessings of Allah be upon him, said:
"Ten things are of the Fitrah: trimming the mustache, letting the beard grow, using the Siwak, rinsing the mouth with water, clipping the nails, washing the knuckles, plucking armpit hair, shaving the pubes and washing after relieving oneself." (Narrated by Muslim)
Medical research has shown us the extreme importance of applying these things, and the harm that results from neglecting them. Letting the nails grow may cause disease, as millions of germs collect underneath them; this has been discussed by specialists. Letting the pubic hair grow is responsible for the disease of pubic lice, which is widespread in Europe and which leads to ulcers and infections in this area.
With regard to circumcision, research has proved that those who are uncircumcised suffer a higher rate of urinary tract disease, caused by a number of germs, especially E. Coli, as well as a higher rate of pus and bacteria in the urine. The link between cervical cancer and non-circumcised men has also been proved.
Washing the knuckles removes colonies of microorganisms that use the folds in the skin in these places to hide in. Plucking the armpit hair cleans this hidden area of the skin in which dirt gathers and germs, especially fungi, grow; some of the germs like to live on the hairs themselves.
(from Islamic Medicine: The Key to a Better Life by Yusuf Al-Hajj Ahmad, Published by Darussalam)
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