Malik related to me from Yahya ibn Said that Said ibn al-Musayyabused to say, "When a man makes his slave-girl mudabbara, he can haveintercourse with her. He cannot sell her or give her away and herchildren are in the same position as her." (ID)
USC-MSA web (English) reference: Book 40, Hadith 5 (ID)
Arabic reference (ID): Book 40, Hadith 1501 (ID)