الزَّانِيَةُ وَالزَّانِي فَاجْلِدُوا كُلَّ وَاحِدٍ مِنْهُمَا مِائَةَ جَلْدَةٍ وَلا تَأْخُذْكُمْ بِهِمَا رَأْفَةٌ فِي دِينِ اللَّهِ إِنْ كُنْتُمْ تُؤْمِنُونَ بِاللَّهِ وَالْيَوْمِ الآخِرِ وَلْيَشْهَدْ عَذَابَهُمَا طَائِفَةٌ مِنَ الْمُؤْمِنِينَ { 2 } الزَّانِي لا يَنْكِحُ إِلا زَانِيَةً أَوْ مُشْرِكَةً وَالزَّانِيَةُ لا يَنْكِحُهَا إِلا زَانٍ أَوْ مُشْرِكٌ وَحُرِّمَ ذَلِكَ عَلَى الْمُؤْمِنِينَ { 3 } سورة النور آية 2-3 قَالَ ابْنُ عُيَيْنَةَ رَأْفَةٌ فِي إِقَامَةِ الْحَدِّ
And both of them should be exiled, as Allah the Exalted has said in Surah An-Nur: "The woman and the man guilty of fornication, flog each of them with a hundred stripes, and let not pity for them detain you in the matter of Allah, if you believe in Allah and the Last Day. And let a party of the believers witness their punishment. Know that the adulterer marries none but an adulteress or a polytheist woman, and the adulteress marries none but an adulterer or a polytheist man, and this is forbidden to the believers." And Sufyan bin ‘Uyaynah said in the explanation of «ولا تأخذكم بهما رأفة في دين الله»: Do not show mercy to them in carrying out the prescribed punishment.
Narrated Zaid bin Khalid Al-Juhani: I heard the Prophet ordering that an unmarried person guilty of illegal sexual intercourse be flogged one-hundred stripes and be exiled for one year.