complete; thus it aligns with the apparent meaning of the text, making it more appropriate than contradicting it. Also, because the ‘idda is a process of istibra’ (clearing the womb), it must therefore be by menstruation, like the istibra’ of a slave woman; this is because istibra’ is for knowing the freedom of the womb from pregnancy, and menstruation indicates this, so it must be the means of istibra’. If it is said: We do not concede that the istibra’ of a slave woman is by menstruation; rather, it is by the period of purity (tuhr) that precedes the menstruation. Ibn ‘Abd al-Barr said this, and he said (28): Their claim that the istibra’ of a slave woman is by one menstruation by consensus is not as they imagined; rather, it is permissible for her in our view to marry when she enters the menstruation, provided she is certain that her blood is menstrual blood. Isma‘il ibn Ishaq said the same to Yahya ibn Aktham when he was brought in (29) to his debate with him. We say: This is refuted by the saying of the Prophet (peace be upon him): "No pregnant woman shall be had intercourse with until she delivers, and no non-pregnant woman until she has been cleared (istubri’at) by one menstruation" (30). Furthermore, it is through istibra’ (31) that the freedom of the womb is known, and it is only achieved by menstruation, not by the period of purity that precedes it. Also, because the ‘idda is [related to the emergence of something from the womb, so it must be related to the period of purity, like the delivery of a pregnancy. This is confirmed by the fact that the ‘idda] (32) has the purpose of knowing (33) the woman’s freedom from pregnancy; sometimes it is achieved by delivery, and sometimes it is achieved by that which contradicts pregnancy, namely menstruation, whose existence is inconceivable during pregnancy. As for (34) His saying, "Then divorce them for their ‘idda," it is possible that He meant before their ‘idda, since it is impossible to interpret it as divorce during the ‘idda, due to the necessity that divorce precedes (35) the ‘idda, because it is its cause, and the cause precedes (36) the ruling, so the ruling (37) cannot exist before it. Thus, divorce during the period of purity is a divorce before the ‘idda if the quru’ are [considered to be] menstruations.