Hadith: Hilāl ibn Umayyah went to the Prophet (may Allah's peace and blessings be upon him) and accused his wife of committing illegal sexual intercourse with Sharīk ibn Sahmā'. The Messenger of Allah (may Allah's peace and blessings be upon him) said: Either you provide proof, or you will receive the legal punishment on your back

عن ابن عباس رضي الله عنهما أن هِلَالَ بن أُمَيَّةَ، قذف امرأته عند النبي صلى الله عليه وسلم بِشَرِيكِ بن سَحْمَاءَ، فقال النبي صلى الله عليه وسلم : «البَيِّنَةَ أو حَدٌّ في ظَهْرِكَ»، فقال: يا رسول الله، إذا رأى أحدنا على امرأته رجلًا ينطلق يَلْتَمِسُ البَيِّنَةَ، فجعل النبي صلى الله عليه وسلم يقول: «البَيِّنَةَ وإلا حد في ظهرك» فقال هلال: والذي بعثك بالحق إني لصادق، فلَيُنْزِلَنَّ الله ما يُبَرِّئُ ظهري من الحد، فنزل جبريل وأنزل عليه: {والذين يرمون أزواجهم} [النور: 6] فقرأ حتى بلغ: {إن كان من الصادقين} [النور: 9] فانصرف النبي صلى الله عليه وسلم فأرسل إليها، فجاء هِلال فشهد، والنبي صلى الله عليه وسلم يقول: «إن الله يعلم أن أحَدَكُمَا كاذب، فهل منكما تائب» ثم قامت فشهدت، فلما كانت عند الخامسة وَقَّفُوهَا، وقالوا: إنها مُوجِبَة، قال ابن عباس: فَتَلَكَّأَتْ وَنَكَصَتْ، حتى ظننا أنها ترجع، ثم قالت: لا أفضح قومي سائر اليوم، فَمَضَتْ، فقال النبي صلى الله عليه وسلم : «أبصروها، فإن جاءت به أَكْحَلَ العينين، سَابِغَ الْأَلْيَتَيْنِ، خَدَلَّجَ الساقين، فهو لِشَرِيكِ بْنِ سَحْمَاءَ»، فجاءت به كذلك، فقال النبي صلى الله عليه وسلم : «لولا ما مضى من كتاب الله لكان لي ولها شأن».
[صحيح] - [متفق عليه واللفظ للبخاري]

Ibn ‘Abbās (may Allah be pleased with him) reported that Hilāl ibn Umayyah went to the Prophet (may Allah's peace and blessings be upon him) and accused his wife of committing illegal sexual intercourse with Sharīk ibn Sahmā'. The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Either you provide proof, or you will receive the legal punishment on your back." Hilāl said: "O Messenger of Allah, if one of us saw a man on top of his wife, should he go and look for witnesses?" The Prophet (may Allah's peace and blessings be upon him) kept saying: "Either you provide proof, or you will receive the legal punishment on your back." Hilāl then said: "By the One Who sent you with the Truth, I am truthful, and Allah will reveal to you what will save my back from the legal punishment." Then (the following) was revealed: {And for those who accuse their wives...} [Sūrat An-Nūr: 24:6] He kept reciting until he reached: {...if he was of the truthful.} [ Sūrat An-Nūr: 24:9]. Then the Prophet (may Allah's peace and blessings be upon him) left and had her summoned. So Hilāl came and took an oath. So the Prophet (may Allah's peace and blessings be upon him) was saying: "Allah knows that one of you is a liar, so, will either of you repent?" Then the woman got up and took the oaths, and when she was about to take the fifth one, the people stopped her and said to her: "It will definitely bring about Allah's curse upon you (if you are guilty)." So she hesitated and recoiled so much that we thought that she would withdraw her denial. But she said: "I will not dishonor my family for the rest of their days." The Prophet (may Allah's peace and blessings be upon him) then said: "Watch her, if she delivers a child with eyes that appear to have kohl on them, big bottoms, and fat shins, then it is Sharīk ibn Sahmā's child." (Later) she gave birth to a child fitting that description. So the Prophet (may Allah's peace and blessings be upon him) said: "If it had not been settled in the Book of Allah, there would have been a matter between me and her."
[Authentic hadith] - [Al-Bukhari and Muslim. This is the wording of Al-Bukhari]

Explanation

This Hadīth indicates that Hilāl ibn Umayyah (may Allah be pleased with him) accused his wife of committing adultery with Sharīk ibn Sahmā'. Therefore, the Prophet (may Allah's peace and blessings be upon him) asked Hilāl to bring proof, and otherwise he would receive the prescribed punishment for false accusations, which consists of flogging one's back. Hilāl wondered if a man should see his wife committing adultery with a man and go find witnesses! However, the Prophet (may Allah's peace and blessings be upon him) insisted on providing the proof, and otherwise the relevant punishment would be applied against the accuser. Abu Ya‘la reprorts in his Musnad on the authority of Anas ibn Mālik that the Prophet (may Allah's peace and blessings be upon him) asked Hilāl to bring four witnesses or else he would apply the prescribed punishment against him. On that, Hilāl swore by Allah, Who sent the Prophet with the truth, that he was saying the truth about his wife's adultery with Sharīk, and prayed that Allah would reveal something that would exonerate him from the punishment. So Jibrīl came down with revelation: {And for those who accuse their wives...} [Sūrat An-Nūr: 6] He recited it until he reached: {...if he was of the truthful} [ Sūrat An-Nūr: 9]. Hilāl came forward and gave his testimony. The Prophet (may Allah's peace and blessings be upon him) said that Allah knew that one of the spouses was lying and wondered if either of them would repent. It seems that the Prophet (may Allah's peace and blessings be upon him) said that after they finished taking their oaths of repudiation. Based on this, the one who lies has to repent. Alternatively, he said that before they took the oaths so as to warn them. The woman also testified. When she was ready to take the fifth oath, the people prevented her from proceeding. They told her that this fifth oath was consequential, for it would remove her from Allah's mercy and incur the torment in the Hereafter upon her if she was not saying the truth. So, as Ibn ‘Abbās said: she slowed down, stopped, and drew back, meaning that she kept silent after the fourth oath. People thought that she would recant her falsification of her husband's charge and her exoneration of herself. She noted that she would not bring shame upon her family for the rest of time by revoking her oath and credit her husband. Therefore, she took the fifth oath of repudiation. The Prophet (may Allah's peace and blessings be upon him) asked the people to check the child that would be born: if he had dark eyelashes, as if he had kohl on them, big buttocks, and fat shins, then the boy was the son of Sharīk ibn Sahmā'. Resemblance is a good proof in cases other than repudiation. The Prophet (may Allah's peace and blessings be upon him) remarked that if it were not the divine judgment that the punishment is inapplicable if the repudiation oaths are taken, he would apply the punishment against the woman. He wanted to make her case a lesson to be learned. That was the first case of Li‘ān in Islam, and verses of the Qur’an were sent down concerning it.