"I heard Sa'eed bin Jubair say: 'I was asked about the two who engage in Li'an during the governorship of Ibn Az-Zubair - should they be separated? I did not know what to say, so I got up and went to the house of Ibn 'Umar and said: "O Abu 'Abdur-Rahman, should the two who engage in Li'an be separated?" He said: "Yes, Subhan Allah! The first one who asked about that was so-and-so the son of so-and-so who said: 'O Messenger of Allah, what do you think if a man among us sees his wife committing immoral actions, and if he speaks of it, he will be speaking of a grave matter, but if he keeps quiet, he will be keeping quiet about a grave matter?' He did not answer him, then after that, he came to him and said: 'I was tried with the matter that I asked you about, so Allah, the Mighty and Sublime, revealed these Verses in Surat An-Nur.: 'And for those who accuse their wives' until he reached: 'And the fifth (testimony) should be that the Wrath of Allah be upon her if he (her husband) speaks the truth.' So he started with the man, exhorting him, reminding him, and telling him that the punishment in this world was less severe than the punishment in the Hereafter. He said: 'By the One Who sent you with the truth, I am not lying.' Then he turned to the woman and exhorted her and reminded her. She said: 'By the One Who sent you with the truth, he is lying.' So he started with the man, and he bore witness four times by Allah that he was telling the truth, and the fifth time (he invoked) the curse of Allah upon himself if he was lying. Then he turned to the woman and she bore witness four times by Allah that he was lying, and the fifth time (she invoked) the wrath of Allah upon herself if he was telling the truth. Then he separated them."'" (Using translation from Nasāʾī 3473)   

يَا رَسُولَ اللهِ أَرَأَيْتَ وَلَمْ يَقُلْ عَمْرٌو أَرَأَيْتَ الرَّجُلُ مِنَّا يَرَى عَلَى امْرَأَتِهِ فَاحِشَةً إِنْ تَكَلَّمَ فَأَمْرٌ عَظِيمٌ قَالَ عَمْرٌو أَتَى أَمْرًا عَظِيمًا وَإِنْ سَكَتَ سَكَتَ عَلَى مِثْلِ ذَلِكَ فَلَمْ يُجِبْهُ فَلَمَّا كَانَ بَعْدَ ذَلِكَ أَتَاهُ فَقَالَ إِنَّ الْأَمْرَ الَّذِي سَأَلْتُكَ ابْتُلِيتُ بِهِ فَأَنْزَلَ اللهُ هَؤُلَاءِ الْآيَاتِ فِي سُورَةِ النُّورِ {وَالَّذِينَ يَرْمُونَ أَزْوَاجَهُمْ} [النور 6] حَتَّى بَلَغَ {وَالْخَامِسَةَ أَنَّ غَضِبَ اللهِ عَلَيْهَا إِنْ كَانَ مِنَ الصَّادِقِينَ} [النور 9] فَبَدَأَ بِالرَّجُلِ فَوَعَظَهُ وَذَكَّرَهُ وَأَخْبَرَهُ أَنَّ عَذَابَ الدُّنْيَا أَهْوَنُ مِنْ عَذَابِ الْآخِرَةِ فَقَالَ وَالَّذِي بَعَثَكَ بِالْحَقِّ مَا كَذَبْتُ ثُمَّ ثَنَّى بِالْمَرْأَةِ فَوَعَظَهَا وَذَكَّرَهَا فَقَالَتْ وَالَّذِي بَعَثَكَ بِالْحَقِّ إِنَّهُ لَكَاذِبٌ فَبَدَأَ بِالرَّجُلِ فَشَهِدَ أَرْبَعَ شَهَادَاتٍ بِاللهِ إِنَّهُ لَمِنَ الصَّادِقِينَ وَالْخَامِسَةَ أَنَّ لَعْنَةَ اللهِ عَلَيْهِ إِنْ كَانَ مِنَ الْكَاذِبِينَ ثُمَّ ثَنَّى بِالْمَرْأَةِ فَشَهِدَتْ أَرْبَعَ شَهَادَاتٍ بِاللهِ إِنَّهُ لَمِنَ الْكَاذِبِينَ وَالْخَامِسَةَ أَنَّ غَضِبَ اللهِ عَلَيْهَا إِنْ كَانَ مِنَ الصَّادِقِينَ فَفَرَّقَ بَيْنَهُمَا