Surah An-Nisa, ayah 16

وَٱلَّذَانِ يَأۡتِيَٰنِهَا مِنكُمۡ فَـَٔاذُوهُمَاۖ فَإِن تَابَا وَأَصۡلَحَا فَأَعۡرِضُواْ عَنۡهُمَآۗ إِنَّ ٱللَّهَ كَانَ تَوَّابٗا رَّحِيمًا ١٦

Walladhāni ya'tiyānihā minkum fa'ādhūhumā fa in tābā wa aslahā fa a'ridū 'anhumā innallāha kāna tawwābar rahīmā

And the two¹⁷¹ who commit it [i.e., unlawful sexual intercourse] among you - punish [i.e., dishonor] them both. But if they repent and correct themselves, leave them alone. Indeed, Allāh is ever Accepting of Repentance and Merciful.