For example...
For example, when he explains the causes for the prohibition of adultery, the Imam (a.s.) says: "Adultery is prohibited due to the corruption it causes such as murders, loss of lineage, child desertion, chaos regarding inheritance, and other such aspects of corruption." Here he determines the social causes behind the prohibition of adultery since the social aspect is more apparent in this case of legislation than any other.
From the same standpoint, the Imam (a.s.) explains to us why usury (riba) is prohibited by saying: "The reason for prohibiting usury is because it eliminates favors, ruins funds, causes greed for profit, causes people to abandon their dealing with loans to each other or in paying cash, or do each other favors, and due to all the bad consequences of corruption and oppression and the exhaustion of funds." As regarding the prohibition of eating the meat of pigs, rabbits, dead animals, spleens, the Imam (a.s.) says: "As regarding pigs, their creation was distorted by God in order to provide a moral lesson to man and in order to remind man to fear God and as an evidence of God's might to distort what He creates at will, and because the food they eat is the filthiest of filth, in addition to many other reasons.
As regarding the rabbits, they are like cats: their claws are like those of the cats and like wild animals, so their behavior is equally wild, in addition to their own inner dirtiness and due to their bleeding which is similar to the bleeding of women during their menstrual period because they are miscreants.
As regarding dead animals, the prohibition of eating their meat is due to the damage such meat will cause to the body, and due to the fact that God has made lawful the meat of animals slaughtered in His name so that that would be a distinction between what is lawful and what is not.
As regarding the spleen, it is prohibited because of the bad blood it contains, and the cause of its prohibition is similar to that of dead animals because it is equally bad in its consequences." These causes, as a whole, justify for us the health aspect necessitated by the legislative interest, its wisdom in safeguarding man against falling a victim to disease and as a preventive measure against ailments.