It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that a man came to the service of the Prophet (peace and blessings of Allah be upon him) and said: O Messenger of Allah (peace and blessings of Allah be upon him)! By Allah! Ever since we irrigated the field after grafting the trees, I have not gone near my wife. The woman's husband had shins and arms, and his hair was straight, while the person with whom the woman was accused was extremely dark-skinned and had curly hair. On this occasion, the Prophet (peace and blessings of Allah be upon him) prayed: "O Allah! Make the reality clear," and had them perform li'an (mutual cursing), and the woman gave birth to a child resembling the person with whom she was accused.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 3360