Abu Sa'id al-Khurdi traced to the Prophet the following statement regarding the captives taken at Autas, “There must be no intercourse with a pregnant woman till she gives birth to her child, or with one who is not pregnant till she has had one menstrual period.”
Abu-d Darda’ said that when the Prophet passed a woman who was near the time to be delivered of a child he asked about her and was told that she was so and so’s slave woman. He asked whether he was having sexual intercourse with her, and when he was told that he was, he said, “I am inclined to invoke a curse on him which will enter his grave with him. How can he take the child into his service when that is not lawful for him, or how can he make it an heir when that is not lawful for him?”*
* The reason for the curse is said to be because he did wait the prescribed period after acquiring the woman and so could not know whether the child was his or not. If he treated the child as a slave he might be enslaving his own son, and if he treated it as an heir he might be doing this to one who was not his son.
Ruwaifi' b. Thabit. reported God’s Messenger as saying on the day of Hunain, “It is not lawful for a man who believes in God and the last day to water what another has sown with his water (meaning intercourse with women who are pregnant); it is not lawful for a man who believes in God and the last day to have intercourse with a captive woman till she has had a menstrual period; and it is not lawful for a man who believes in God and the last day to sell spoil till it is divided.”
Abu Dawud transmitted it, and Tirmidhi transmitted it up to “what another has sown with his water.”
Sa'id b. al-Musayyib reported ‘Umar b. al-Khattab as saying, “If any woman is divorced and has one or two menstrual periods then stops menstruating she must wait nine months, and if it is apparent that she is pregnant the rules concerning that are applied; otherwise she must observe a period of three months after the nine months are ended, after which she may lawfully remarry.