The Quran

Preface

الزّانِيَةُ وَالزّاني فَاجلِدوا كُلَّ واحِدٍ مِنهُما مِائَةَ جَلدَةٍ ۖ وَلا تَأخُذكُم بِهِما رَأفَةٌ في دينِ اللَّهِ إِن كُنتُم تُؤمِنونَ بِاللَّهِ وَاليَومِ الآخِرِ ۖ وَليَشهَد عَذابَهُما طائِفَةٌ مِنَ المُؤمِنينَ

Yusuf Ali

The woman and the man guilty of adultery or fornication,-¹ flog each of them with a hundred stripes:² Let not compassion move you in their case, in a matter prescribed by God, if ye believe in God and the Last Day: and let a party of the Believers witness their punishment.³

Zinā includes sexual intercourse between a man and a woman not married to each other. It therefore applies both to adultery (which implies that one or both of the parties are married to a person or persons other than the ones concerned) and to fornication, which, in its strict signification, implies that both parties are unmarried. The law of marriage and divorce is made easy in Islam, so that there may be less temptation for intercourse outside the well-defined incidents of marriage. This makes for greater self-respect for both man and woman. Other sex offences are also punishable, but this Section applies strictly to Zinā as above defined.
Cf. 4:15, n. 523 and 33:30.
The punishment should be public, in order to be deterrent.