Allaah Almighty Says in the Noble Quran (what means):
“The [Unmarried] woman or [unmarried] man found guilty of sexual intercourse— lash each one of them with a hundred lashes, and do not be taken by pity for them in the religion [i.e. law] of Allaah, if you should believe in Allaah and the Last Day. And let a group of the believers witness their punishment. The fornicator does not marry except a [female] fornicator or polytheist, and none marries her except a fornicator or a polytheist, and that [i.e. marriage to such persons] has been made unlawful to the believers. And those who accuse chaste women (of adultery) and then do not produce four witnesses — lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient. Except for those who repent thereafter and reform, for indeed Allaah is Forgiving and Merciful.” [Quran 24: 2-5]
Islamic law (Sharee’ah) prescribes a very heavy penalty for adultery. However, Islam does not legislate such a penalty without first putting in place sufficient legislation that protects people against falling in sin. It also ensures that the punishment is not enforced except in cases where there is certainty about the offence and its perpetrators. Islam is a complete code of living that is not based on punishment. Its basis is to provide all that promotes a clean and morally pure life. If some individuals then abandon such a clean and easy life in order to deliberately submerge themselves into filth, they incur such heavy penalty.
In the case of adultery, Islam requires four witnesses to testify that they have seen the offence, or else, a clear and confirmed confession by the perpetrators.
It may be suggested, then, that the punishment is unreal and unenforceable, which renders it ineffective as a deterrent. Punishment is not the basis of the Islamic approach; its basis is prevention, education and cultivating people’s finer feelings and consciences so that they refrain from even contemplating this offence.