Hadith 10:523
Abu Bakr narrated to us, he said: Zayd ibn al-Hubab narrated to us, from Sayf, from Mujahid, who said: If a slave woman is under a free man, her divorce is two [pronouncements] and her waiting period is two menstrual cycles. And if a free woman is under a slave, her divorce is three [pronouncements] and her waiting period is three menstrual cycles.
حدثنا أبو بكر قال نا زيد بن الحباب عن سيف عن مجاهد قال إذا كانت الأمة تحت الحر فطلاقها اثنتان وعدتها حيضتان وإذا كانت الحرة تحت العبد فطلاقها ثلاث وعدتها ثلاث حيض