Qur'ān 17:32 · Al-Isra (الإسراء)

وَلَا تَقْرَبُوا۟ ٱلزِّنَىٰٓ ۖ إِنَّهُۥ كَانَ فَـٰحِشَةًۭ وَسَآءَ سَبِيلًۭا

And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way.