During Jihad (religion war), many men and women become war captives. The Amirul Mu’minin [leader of the believers, or caliph—an office now vacant] has the choice of distributing them amongst the Mujahidin [warriors of jihad], in which event they will become the property of these Mujahidin. This enslavement is the penalty for disbelief (kufr).
Source, in full
Tafsir Anwarul Bayan , I, 501. about Quran 4.3.Muhammad Aashiq Ilahi Bulandshahri, Illuminating Discourses on the Noble Qur’an (Tafsir Anwarul Bayan ), Afzal Hussain Elias and Muhammad Arshad Fakhri, trans. (Karachi: Darul Ishaat, 2005) quoted in The critical qur’an: explained from key islamic commentaries and contemporary historical research. (2021). . Bombardier Books.