Book of Fornication (Zinā)
Zinā that entails the ḥadd penalty is defined as the penetration of the penis into a private part that is intrinsically unlawful, free of any legal doubt, and sought out of sexual desire. According to the Shāfiʿī school, penetration of the anus—whether of a male or a female—carries the same ruling as penetration of the front.
No ḥadd is incurred for mere interfemoral contact (mufākhadha), or for intercourse with one’s wife or slave-girl during menstruation, fasting, or iḥrām. The same applies to intercourse with one’s slave-girl who is married to someone else, in her waiting period, or permanently unlawful to him, and likewise for the coerced party, in the more reliable view. Any situation that a recognised jurist has deemed permissible—such as a marriage conducted without witnesses, according to the sound position—also precludes the ḥadd, as does intercourse with a corpse (on the soundest view) or with an animal (on the preponderant view).
The ḥadd is enforced, however, for intercourse with a woman hired for that purpose, a woman who simply offers herself, or a woman permanently forbidden in marriage, even if he has purported to marry her. Liability requires legal competence (taklīf), with the exception that the intoxicated person remains liable, and it requires awareness of the act’s prohibition.
The punishment for the muḥṣan is stoning. A muḥṣan is a legally competent, free person—even a dhimmī—who has previously inserted the glans into a vagina within a valid (not defective) marriage. The sounder opinion further stipulates that this prior penetration occurred while he was free and legally competent, and that someone who meets these requirements remains muḥṣan even if the partner in the present offence does not.
The penalty for a free bachelor (non-muḥṣan) is one hundred lashes and banishment for one full year to a place at least the distance that allows the shortening of prayers or farther. If the ruler designates a particular place of exile, the offender may not, according to the sound view, request another. A stranger who commits zinā in a land other than his own is banished to somewhere other than his home town; if he returns, he is prevented from entering, on the stronger opinion. A woman is not exiled by herself, on the soundest view; rather she must be accompanied by her husband or a male guardian, even if one must be hired, and if the guardian refuses to accompany her for payment