It was reported from Imam al-Sadiq (a.

It was reported from Imam al-Sadiq (a.s.) that, “The Holy Prophet (s.a.w.s.) prohibited defecation on the edge of a well, river or under a fruit tree.”17 And it was also reported from the Holy Prophet (s.a.w.s.) that, “It is prohibited for man to urinate in stationary water…”18 And he (a.s.) also quoted the Holy Prophet (s.a.w.s.) that he said: “Surely, the Almighty Allah warns you, oh, my (followers) Ummah!, against twenty four things and prohibits you from them,” and he recited them until he said , “He warns against urinating on the edge of a running river.”19 Prohibition on staying in a state with***“najasah”*** (unclean things) and their purification: When we read the philosophy of Islamic laws, we will be able to detect the concern and care of these laws toward man’s protection.

The Jurists*(Fuqaha)* have summarized the philosophy of Islamic laws and analyzed them in a simple formula, i.e., “attracting to the best interest*(masalih)* and repelling evil (corruption) (mafasid).” Hence, “masalaha” and*“mafasada”* are the two criteria of a particular law and the cause of its legislation.

And, of course, at the time of practicing this legislative principle on things which Islamic laws prescribe, like the impurity of some things, and the prohibition of eating and selling them and the necessity of purifying them before praying, one will then understand the value and worth against evil which is harmful to the health.

It is in view of this that the Islamic Shari‘a terms the following things as*“najis”* and necessitates its purification before praying and circumambulation*(Tawaf,* ritual circling of the Ka‘ba) and they are: Human urine and feces, and likewise, the urine and feces of those animals forbidden for us to eat. The dead body of humans, and animals whose blood gushes out when slaughtered. Human sperm, as well as that of animals whose blood gushes out when slaughtered.

Human blood, as well as that of animals whose blood gushes out when slaughtered. Alcoholic liquors. Terrestrial dogs and pigs. Undoubtedly, the present man’s problem, especially in big cities, is how to get rid of human and animal waste products, as well as their dead bodies. This is because they are the most clear and wide range source of microbes and other dangerous diseases, which afflict man.