Surah An-Noor, Verse 2
ٱلزَّانِيَةُ وَٱلزَّانِى فَٱجْلِدُوا۟ كُلَّ وَٰحِدٍۢ مِّنْهُمَا مِا۟ئَةَ جَلْدَةٍۢ ۖ وَلَا تَأْخُذْكُم بِهِمَا رَأْفَةٌۭ فِى دِينِ ٱللَّهِ إِن كُنتُمْ تُؤْمِنُونَ بِٱللَّهِ وَٱلْيَوْمِ ٱلْءَاخِرِ ۖ وَلْيَشْهَدْ عَذَابَهُمَا طَآئِفَةٌۭ مِّنَ ٱلْمُؤْمِنِينَ
Translation — Sahih International
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 of Allah, if you should believe in Allah and the Last Day. And let a group of the believers witness their punishment.
Source
Kur'an-ı Kerim, Nûr Suresi 24:2
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/24-suresi-2-ayet