Musnad Ahmad 3:104

Yazid narrated to us, Mahdi ibn Maymun informed us, from Muhammad ibn Abdullah ibn Abi Ya’qub, from al-Hasan ibn Sa’d, who said: Rabah narrated to me, saying: My master married me to a Roman slave girl. I had intercourse with her, and she bore me a black boy like myself, so I named him Abdullah. Then I had intercourse with her, and she bore me a black boy like myself, so I named him Ubaydullah. Then a Roman boy was brought to me—he said: I think he said: for my family, a Roman—who was called Yuhannis. He spoke to her in his language—meaning in Roman—and he had intercourse with her. She then bore him a red boy, as if he were a gecko among the geckos. I said to her: "What is this?" She said: "This is from Yuhannis." He said: So we went up to Uthman ibn Affan, and they both confessed. Uthman said: "If you wish, I will judge between you with the judgment of the Messenger of Allah, peace and blessings of Allah be upon him. The Messenger of Allah, peace and blessings of Allah be upon him, judged that the child belongs to the bed." He said: I think he said: "And he flogged them both."