Sahih Bukhari, Chapter: Manumission of Slaves

Utba bin Abi Waqqas authorized his brother Sad bin Abi Waqqas to take the son of the slave-girl of Zama into his custody, telling him that the boy was his own (illegal) son. When Allah's Apostle (SAW) went (to Makkah) at the time of the Conquest, Sad took the son of the slavegirl of Zama to Allah's Apostle (SAW) and also brought Abd bin Zama with him and said, "O Allah's Apostle (SAW)! This is the son of my brother Utba who authorised me to take him into my custody." Abd bin Zama said, "O Allah's Apostle (SAW)! He is my brother, the son of Zama's slave-girl and he was born on his bed." Allah's Apostle (SAW) looked at the son of the slave-girl of Zama and noticed much resemblance (to Utba). Allah's Apostle (SAW) said, "It is for you, O Abd bin Zama as he was born on the bed of your father." Allah's Apostle (SAW) then told Sauda bint Zama to observe veil in the presence of the boy as he noticed the boy's resemblance to Utba and Sauda was the wife of the Prophet (SAW).