"We have also seen that according to the prevalent view of the traditionists, a female polytheist must be converted to Islam, by coercive measures if necessary, before any sexual relationship with her can take place... Conversion to Islam is not mentioned here as a necessary condition for sexual relations. In the opinion of Mujahid, the captive girl should shave her pubic hair, trim her hair and pare her nails. Then she should perform ablution, wash her clothes, pronounce the shahada and perform a Muslim prayer. But even if she refuses to do these things, her master is still allowed to have sexual relations with her once she has had one menstrual period in his house. And Safiıd b. al-Musayyab simply says that “there is nothing wrong in a man having sexual relations with his Zoroastrian slave-girl”... Ibn Qayyim al-Jawziyya observes, on the other hand, that: "they (i.e., the Prophet’s companions) did not make sexual relations with Arab captives contingent on their conversion; rather they had sexual relations with them after one menstrual period. God allowed them to do this and did not make it conditional on conversion." Summing up, Ibn Qayyim al-Jawziyya says that there is not a single tradition which makes sexual relations with female captives contingent on their conversion."
January 1, 1970
https://en.wikiquote.org/wiki/Women's_rights_in_Iran