سورة المؤمنون

Imam Ali (peace be upon him): أَوْ ما مَلَکَتْ أَیْمانُهُمْ [Or those whom their right hands possess] means the slave-women, فَإِنَّهُمْ غَیْرُ مَلُومِینَ [for they surely are not blameable]. The limits and rulings of mut'ah (temporary marriage) are also like the rulings pertaining to slave-women.

Imam Sadiq (peace be upon him): There are ten categories of slave-women with whom intercourse is not permitted: combining a mother and her daughter; combining two sisters; your slave-woman who is pregnant by someone other than you, until she gives birth; your slave-woman who is your paternal aunt through breastfeeding; your slave-woman who is your maternal aunt through breastfeeding; your slave-woman who is your sister through breastfeeding; your slave-woman who is considered your niece through breastfeeding; your slave-woman whom you own but who has a husband; one who is in the waiting-period ('iddah) of another; and lastly, a slave-woman in whom you have a partner.