Sunan an-Nasa'i, Book 27, Hadith 78 (In-Book) ⓘ

It was narrated from Sahl bin Sa'd, from 'Asim bin 'Adiyy who said: "Uwaimir, a man from Banu 'Ajlan, came and said: 'O 'Asim, what do you think if a man sees another man with his wife, should he kill him and be killed in retaliation, or what should he do? O 'Asim, ask the Messenger of Allah about that for me.'" So 'Asim asked the Messenger of Allah about that, and the Messenger of Allah disapproved of the question and criticized the asking of too many questions. Then 'Uwaimir came to him and said: "What happened, O 'Asim?" 'Asim said to 'Uwaimir: "What happened?! You have not brought me any good. The Messenger of Allah disapproved of the question I asked." 'Uwaimir said: "By Allah, I will go and ask the Messenger of Allah." So he went to the Messenger of Allah and asked him. The Messenger of Allah said: "Allah the Mighty and Sublime has revealed (something) concerning you and your wife, so bring her here." Sahl said: "I was among the people in the presence of the Messenger of Allah and he brought her and they engaged in the procedure of Li'an. He said: 'O Messenger of Allah, by Allah! If I keep her I would have been telling lies about her.' So he parted from her before the Messenger of Allah told him to separate from her, and that became the way of Li'an."

أَخْبَرَنَا مُحَمَّدُ بْنُ مَعْمَرٍ، قَالَ حَدَّثَنَا أَبُو دَاوُدَ، قَالَ حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ أَبِي سَلَمَةَ، وَإِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ الزُّهْرِيِّ، عَنْ سَهْلِ بْنِ سَعْدٍ، عَنْ عَاصِمِ بْنِ عَدِيٍّ، قَالَ جَاءَنِي عُوَيْمِرٌ - رَجُلٌ مِنْ بَنِي الْعَجْلاَنِ - فَقَالَ أَىْ عَاصِمُ أَرَأَيْتُمْ رَجُلاً رَأَى مَعَ امْرَأَتِهِ رَجُلاً أَيَقْتُلُهُ فَتَقْتُلُونَهُ أَمْ كَيْفَ يَفْعَلُ يَا عَاصِمُ سَلْ لِي رَسُولَ اللَّهِ صلى الله عليه وسلم ‏.‏ فَسَأَلَ عَاصِمٌ عَنْ ذَلِكَ النَّبِيَّ صلى الله عليه وسلم فَعَابَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْمَسَائِلَ وَكَرِهَهَا ‏.‏ فَجَاءَهُ عُوَيْمِرٌ فَقَالَ مَا صَنَعْتَ يَا عَاصِمُ فَقَالَ صَنَعْتُ أَنَّكَ لَمْ تَأْتِنِي بِخَيْرٍ كَرِهَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْمَسَائِلَ وَعَابَهَا ‏.‏ قَالَ عُوَيْمِرٌ وَاللَّهِ لأَسْأَلَنَّ عَنْ ذَلِكَ رَسُولَ اللَّهِ صلى الله عليه وسلم ‏.‏ فَانْطَلَقَ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَسَأَلَهُ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ قَدْ أَنْزَلَ اللَّهُ عَزَّ وَجَلَّ فِيكَ وَفِي صَاحِبَتِكَ فَائْتِ بِهَا ‏" ‏ ‏.‏ قَالَ سَهْلٌ وَأَنَا مَعَ النَّاسِ عِنْدَ رَسُولِ اللَّهِ صلى الله عليه وسلم فَجَاءَ بِهَا فَتَلاَعَنَا فَقَالَ يَا رَسُولَ اللَّهِ وَاللَّهِ لَئِنْ أَمْسَكْتُهَا لَقَدْ كَذَبْتُ عَلَيْهَا ‏.‏ فَفَارَقَهَا قَبْلَ أَنْ يَأْمُرَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم بِفِرَاقِهَا فَصَارَتْ سُنَّةَ الْمُتَلاَعِنَيْنِ ‏.‏