﴿ وَٱلَّذِينَ يَرْمُونَ ٱلْمُحْصَنَٰتِ ثُمَّ لَمْ يَأْتُوا۟ بِأَرْبَعَةِ شُهَدَآءَ فَٱجْلِدُوهُمْ ثَمَٰنِينَ جَلْدَةًۭ وَلَا تَقْبَلُوا۟ لَهُمْ شَهَٰدَةً أَبَدًۭا ۚ وَأُو۟لَٰٓئِكَ هُمُ ٱلْفَٰسِقُونَ ﴾

“And as for those who accuse chaste women [of adultery], and then are unable to produce four witnesses [in support of their accusation], flog them with eighty stripes and ever after refuse to accept from them any testimony - since it is they, they that are truly depraved!”

Please check ayah 24:5 for complete tafsir.