It is narrated from Sayyiduna Sahl bin Sa’d Sa’idi (may Allah be pleased with him) that Sayyiduna Uwaymir ‘Ajlani (may Allah be pleased with him) came to Sayyiduna ‘Asim bin ‘Adi (may Allah be pleased with him) and asked,“If a person finds another man with his wife, what should he do? If he kills him, he himself will be killed. Ask the Messenger of Allah (peace and blessings of Allah be upon him) about this issue for me.”Sayyiduna ‘Asim (may Allah be pleased with him) asked the Messenger of Allah (peace and blessings of Allah be upon him) about this issue, and the Messenger of Allah (peace and blessings of Allah be upon him) disliked this question and spoke harshly about it. This matter was very difficult for Sayyiduna ‘Asim (may Allah be pleased with him). When he returned home, Sayyiduna Uwaymir ‘Ajlani (may Allah be pleased with him) came and asked,“What did the Messenger of Allah (peace and blessings of Allah be upon him) say?”Sayyiduna ‘Asim (may Allah be pleased with him) said,“I did not benefit from you; the Messenger of Allah (peace and blessings of Allah be upon him) disliked this question.”Sayyiduna Uwaymir ‘Ajlani (may Allah be pleased with him) said,“By Allah! I will not rest until I ask the Messenger of Allah (peace and blessings of Allah be upon him) myself.”Then Sayyiduna Uwaymir ‘Ajlani (may Allah be pleased with him) came to the Messenger of Allah (peace and blessings of Allah be upon him) while the people were all gathered, and he asked,“O Messenger of Allah (peace and blessings of Allah be upon him)! If a man finds another man with his wife and kills him, he himself will be killed. What should he do?”The Messenger of Allah (peace and blessings of Allah be upon him) said,“Allah’s command has come regarding you and your wife. Bring your wife.”Sayyiduna Sahl (may Allah be pleased with him) says: Both of them came and performed li’an (mutual cursing) before the Messenger of Allah (peace and blessings of Allah be upon him), and I was present at that time. When they finished the li’an, Sayyiduna Uwaymir ‘Ajlani (may Allah be pleased with him) said,“O Messenger of Allah (peace and blessings of Allah be upon him)! If I keep this woman, it is as if I have lied,”and with that, he pronounced three divorces without the Messenger of Allah (peace and blessings of Allah be upon him) telling him to do so. Ibn Shihab said: Then this became the established practice for those who perform li’an.