Surah An-Noor Verse 6

وَالَّذِينَ يَرْمُونَ أَزْوَاجَهُمْ وَلَمْ يَكُن لَّهُمْ شُهَدَاءُ إِلَّا أَنفُسُهُمْ فَشَهَادَةُ أَحَدِهِمْ أَرْبَعُ شَهَادَاتٍ بِاللَّهِ ۙ إِنَّهُ لَمِنَ الصَّادِقِينَ

Wallazeena yarmoona azwaajahum wa lam yakul lahum shuhadaaa'u illaaa anfusuhum fashahaadatu ahadihim arb'u shahaadaatim billaahi innahoo laminas saadiqeen

Translation / The Meaning

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.