Yahya related to me from Malik from Ibn Shihab from Abu Abd ar-Rahman that Zayd ibn Thabit said that if a man divorced his slave-girlthree times and then bought her, she was not halal for him until shehad married another husband. (ID)
USC-MSA web (English) reference: Book 28, Hadith 30 (ID)
Arabic reference (ID): Book 28, Hadith 1124 (ID)