An-Nur 24:9

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

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.

وَالْخَامِسَةُ أَنَّ لَعْنَتَ اللَّهِ عَلَيْهِ إِن كَانَ مِنَ الْكَاذِبِينَ

And the fifth [oath will be] that the curse of Allah be upon him if he should be among the liars.

وَيَدْرَأُ عَنْهَا الْعَذَابَ أَن تَشْهَدَ أَرْبَعَ شَهَادَاتٍ بِاللَّهِ ۙ إِنَّهُ لَمِنَ الْكَاذِبِينَ

But it will prevent punishment from her if she gives four testimonies [swearing] by Allah that indeed, he is of the liars.

وَلَوْلَا فَضْلُ اللَّهِ عَلَيْكُمْ وَرَحْمَتُهُ وَأَنَّ اللَّهَ تَوَّابٌ حَكِيمٌ

And if not for the favor of Allah upon you and His mercy... and because Allah is Accepting of repentance and Wise.

إِنَّ الَّذِينَ جَاءُوا بِالْإِفْكِ عُصْبَةٌ مِّنكُمْ ۚ لَا تَحْسَبُوهُ شَرًّا لَّكُم ۖ بَلْ هُوَ خَيْرٌ لَّكُمْ ۚ لِكُلِّ امْرِئٍ مِّنْهُم مَّا اكْتَسَبَ مِنَ الْإِثْمِ ۚ وَالَّذِي تَوَلَّىٰ كِبْرَهُ مِنْهُمْ لَهُ عَذَابٌ عَظِيمٌ

Indeed, those who came with falsehood are a group among you. Do not think it bad for you; rather it is good for you. For every person among them is what [punishment] he has earned from the sin, and he who took upon himself the greater portion thereof - for him is a great punishment.

لَّوْلَا إِذْ سَمِعْتُمُوهُ ظَنَّ الْمُؤْمِنُونَ وَالْمُؤْمِنَاتُ بِأَنفُسِهِمْ خَيْرًا وَقَالُوا هَـٰذَا إِفْكٌ مُّبِينٌ

Why, when you heard it, did not the believing men and believing women think good of one another and say, "This is an obvious falsehood"?