Sunan Ibn Majah, Chapter: The Chapters on Marriage

Ibn Zamah and Sa'd (Ibn Abu Waqqas) referred a dispute to the Prophet (saw) concerning the son of Zamah's slave woman. Sa'd said : " O Messenger of Allah (saw) my brother (Utbah bin Abu Waqqas) left instructions in his will that when I come to Makkah, I should look for the son of the slave woman of Zamah and take him into my care." Abd bin Zam’ah said: "He is my brother and the son of the slave woman of my father; he was born on my father's bed." The Prophet (saw) ffi saw that he resembled 'Utbah, and said: "He belongs to you, O Abd bin Zamah. The child is for the bed. Observe Hijab before him, O Saudah." (sahih)