In classical Islamic jurisprudence, the use of female captives taken in a lawful war (malikat al-yamin or concubines) is legally tied to the laws of jihad, the status of non-combatants, and the socio-economic framework of pre-modern statecraft. Muslim jurists argued that enslavement and concubinage served as an alternative to execution or perpetual imprisonment, while integrating captives into households with defined legal rights. 

Legal and Theological Framework

Law of War: Classical jurists restricted this status strictly to women captured during a legitimate, declared military conflict against hostile combatants (harbis).
Alternative to Captivity: Jurists viewed enslavement as a lesser harm compared to execution or abandonment on the battlefield in eras before international prisoner-of-exchange treaties.
Ownership and Access: Islamic law permitted a master to have intimate relations with his female slave, treating her as a recognized form of lawful union distinct from formal marriage (nikah).