Is a previously enslaved pagan woman lawful to her master if she converts to Islam before her prescribed waiting period ('istibra') is complete?

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If a master owns a Magian or idol worshipper who converts to Islam before her prescribed waiting period (istibra) is finished, she is not lawful to him until she completes the remainder of the istibra. If she completes the istibra and then converts, she becomes lawful to him without needing a new istibra. The basis for this ruling is the Hadith stating, 'No woman who is not menstruating shall be touched sexually until she has undergone istibra by one menstrual cycle.' This command was given regarding captives of Aws and Uthas, who were polytheists, and the Prophet (peace be upon him) did not command more than one menstrual cycle for them. Furthermore, the master's ownership was not renewed, nor did another person have sexual intercourse with her, thus negating the need for a new istibra, similar to a woman who was previously forbidden (muharramah) becoming permissible again.