The third section: That the menstruation in which he divorces (38) her is not counted as part of her 'idda, without any disagreement among the scholars; because Allah the Almighty commanded three quru', which encompasses three complete ones, and the one in which he divorced her does not have remaining from it that which would complete, with two others, three full ones, so it is not counted. And because divorce was prohibited during menstruation on account of the prolongation of the 'idda it entails upon her; so if that menstruation were counted as a qur', it would have been shorter for her 'idda and more beneficial to her, and thus it would not have been prohibited (40). As for those who say: The quru' are the periods of purity (at-tuhur), [they counted for her the period of purity in which he divorced her as a qur'. If he divorced her while a moment remained of her qur', he counted it as a qur', and this is the statement of everyone who said: The quru' are the periods of purity] (41). Except for al-Zuhri alone; he said: She observes the 'idda for three (42) quru' excluding the period of purity in which he divorced her. It was narrated from Abu 'Ubayd that if he had intercourse with her during the period of purity, he would not count the remainder of it, because it is a time in which divorce was prohibited, so he did not count it (43) as part of the 'idda, like the time of menstruation. As for us, divorce was prohibited during the time of menstruation in order to avert the harm of prolonging the 'idda for her. If the remainder of the period of purity were not counted as a qur', then divorce during the period of purity would be more harmful to her and longer for her. What is mentioned from Abu 'Ubayd is not valid; because the prohibition of divorce during menstruation is because she does not count the remainder of it, so it is not permissible to make the cause of non-counting the prohibition of divorce, as the cause would become the caused. Rather, the prohibition of divorce during the period of purity in which he had intercourse with her is because she is in a state of doubt, and because he cannot be certain that he will not regret it due to the potential appearance of her pregnancy. As for if the words of divorce are completed with the completion of the period of purity, then the divorce occurs at (45) the beginning of the menstruation, it is prohibited, and she does not count that menstruation as part of her 'idda.