Qur'an 24:6 · An-Noor

وَٱلَّذِينَ يَرْمُونَ أَزْوَٰجَهُمْ وَلَمْ يَكُن لَّهُمْ شُهَدَآءُ إِلَّآ أَنفُسُهُمْ فَشَهَٰدَةُ أَحَدِهِمْ أَرْبَعُ شَهَٰدَٰتٍۭ بِٱللَّهِ ۙ إِنَّهُۥ لَمِنَ ٱلصَّٰدِقِينَ

(6) And those who accuse their wives [of adultery] and have no witnesses except themselves - then the witness of one of them[976] [shall be] four testimonies [swearing] by Allāh that indeed, he is of the truthful.