Qur'ān 4:15 · An-Nisa (النساء)

وَٱلَّـٰتِى يَأْتِينَ ٱلْفَـٰحِشَةَ مِن نِّسَآئِكُمْ فَٱسْتَشْهِدُوا۟ عَلَيْهِنَّ أَرْبَعَةًۭ مِّنكُمْ ۖ فَإِن شَهِدُوا۟ فَأَمْسِكُوهُنَّ فِى ٱلْبُيُوتِ حَتَّىٰ يَتَوَفَّىٰهُنَّ ٱلْمَوْتُ أَوْ يَجْعَلَ ٱللَّهُ لَهُنَّ سَبِيلًۭا

Those who commit unlawful sexual intercourse of your women - bring against them four [witnesses] from among you. And if they testify, confine the guilty women to houses until death takes them or Allah ordains for them [another] way.