As for those who accuse their own spouses, without any other witnesses, then the testimony may be accepted if he swears by God four times that he is telling the truth.
وَالَّذينَ يَرمونَ أَزوٰجَهُم وَلَم يَكُن لَهُم شُهَداءُ إِلّا أَنفُسُهُم فَشَهٰدَةُ أَحَدِهِم أَربَعُ شَهٰدٰتٍ بِاللَّهِ إِنَّهُ لَمِنَ الصّٰدِقينَ
wallazeena yarmoona azwaajahum wa lam yakul lahum shuhadaaa’u illaaa anfusuhum fashahaadatu ahadihim arba’u shahaadaatim billaahi innahoo laminas saadiqeen