Musnad Ahmad 1153:77

Sufyan narrated to us, from al-Zuhri, from Urwah, from Aisha: Abd ibn Zam'ah and Sa'd ibn Abi Waqqas disputed before the Prophet, peace and blessings of Allah be upon him, regarding the son of Zam'ah's slave-woman. Abd said: "O Messenger of Allah, he is my brother, the son of my father's slave-woman, born upon my father's bed." Sa'd said: "My brother entrusted me, saying: 'When you arrive in Mecca, look for the son of Zam'ah's slave-woman and take him, for he is my son.'" The Prophet, peace and blessings of Allah be upon him, saw a clear resemblance to Utbah. He said: "He is yours, O Abd. The child is for the bed, and observe hijab from him, O Sawdah."