Ubaydullah bin Abdullah bin Utbah (may Allah have mercy on him) said: Abd al-Malik bin Marwan asked Abdullah bin Utbah (may Allah have mercy on him): Does a slave-woman make a free man muhsan? He said: Yes. He asked: From whom do you narrate this? He said: We heard the Companions of the Messenger (may Allah be pleased with them) saying so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 16943