Sahih Bukhari Volume 9, Book 92, Hadith Number 407.

Narrated By Sahl bin Sa’d As-Sa’idi : ‘Uwaimir Al-‘Ajlani came to ‘Asim bin ‘Adi and said, “If a man found another man with his wife and killed him, would you sentence the husband to death (in Qisas,) i.e., equality in punishment)? O ‘Asim! Please ask Allah’s Apostle about this matter on my behalf.” ‘Asim asked the Prophet but the Prophet disliked the question and disapproved of it. ‘Asim returned and informed ‘Uwaimir that the Prophet disliked that type of question. ‘Uwaimir said, “By Allah, I will go (personally) to the Prophet.” ‘Uwaimir came to the Prophet when Allah had already revealed Qur’anic Verses (in that respect), after ‘Asim had left (the Prophet). So the Prophet said to ‘Uwaimir, “Allah has revealed Qur’anic Verses regarding you and your wife.” The Prophet then called for them, and they came and carried out the order of Lian.

Then ‘Uwaimir said, “O Allah’s Apostle! Now if I kept her with me, I would be accused of telling a lie.” So ‘Uwaimir divorced her although the Prophet did not order him to do so. Later on this practice of divorcing became the tradition of couples involved in a case of Li’an. The Prophet said (to the people). “Wait for her! If she delivers a red short (small) child like a Wahra (a short red animal). then I will be of the opinion that he (‘Uwaimir) has told a lie but if she delivered a black big-eyed one with big buttocks, then I will be of the opinion that he has told the truth about her.” ‘Ultimately she gave birth to a child that proved the accusation. (See Hadith No. 269, Vol. 6)