Sahih Muslim 1496

Muhammad ibn al-Muthanna narrated to us; Abd al-Ala narrated to us; Hisham narrated to us, from Muhammad, who said: I asked Anas ibn Malik, thinking that he had knowledge of this matter. He said: Hilal ibn Umayyah accused his wife of adultery with Sharik ibn Sahma, who was the maternal half-brother of al-Bara ibn Malik. He was the first man to invoke mutual curses in Islam. He said: He invoked mutual curses with her. The Messenger of Allah (peace and blessings be upon him) said: Look at the child: if she gives birth to a fair-skinned child with straight hair and bright eyes, he is Hilal ibn Umayyahs; but if she gives birth to a dark-eyed child with curly hair and thin shanks, he is Sharik ibn Sahmas. He said: I was informed that she gave birth to a dark-eyed child with curly hair and thin shanks.