وَالَّذينَ يَرمونَ أَزواجَهُم وَلَم يَكُن لَهُم شُهَداءُ إِلّا أَنفُسُهُم فَشَهادَةُ أَحَدِهِم أَربَعُ شَهاداتٍ بِاللَّهِ ۙ إِنَّهُ لَمِنَ الصّادِقينَ

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