Hadith.4545 - Abdullah ibn al-Qasim narrated from Abdullah ibn Sinan, who said: I asked Abu Abdillah (as): "I purchase a bondwoman from a trustworthy man who informs me that he has not touched her since she menstruated and then purified herself. Is it permissible for me to have relations with her?" Imam (as) said: "It is not permissible for you to have relations with her until she undergoes one menstrual cycle (for istibra'). However, you are allowed to engage in activities other than intercourse. Indeed, those who purchase bondwomans and have relations with them before ensuring they are free from pregnancy through istibra', such people are committing adultery with their wealth."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.

Hadith.4547 - Al-Alaa narrated from Muhammad ibn Muslim, who said: I asked him about a man who purchased a bondwoman and her previous owner had not had relations with her. Should he still observe an istibra' (waiting period) for her womb? Imam (as) said: "Yes." I asked: "What about a bondwoman who has not yet menstruated? What should he do with her?" Imam (as) said: "Her matter is more severe. If he has relations with her, he must not ejaculate until it becomes clear whether she is pregnant or not." I asked: "How long will it take for this to become clear?" Imam (as) said: "In forty-five nights."

Translation: Bab Ul Qaim Publications — attributed by Thaqalayn·The Arabic above is the original.