Abu Dawud Book 6, Hadith Number 2268.
Narated By Uthman ibn Affan : Rabah said: My people married me to a Roman slave-girl of theirs. I had intercourse with her, and she gave birth to a black (male) child like me. I named it Abdullah. I again had intercourse with her, and she gave birth to a black (male) child like me. I named it Ubaydullah. Then a Roman slave of my people, called Yuhannah, incited her, and spoke to her in his own unintelligible language. She gave birth to a son like a chameleon (red).
I asked her: What is this? She replied: This belongs to Yuhannah. We then brought the case to Uthman (for a decision). I think Mahdi said these words. He inquired from both of them, and they acknowledged (the facts).
He then said to them: Do you agree that I take the decision about you, which the Apostle of Allah (PBUH) had taken? The Apostle of Allah (PBUH) decided that the child was to attributed to the one on whose bed it was born. And I think he said: He flogged her and flogged him, for they were slaves.