His statement, “If he has intercourse with the woman whom he has declared unlawful to himself by zihār, whether by night or by day, the consecutiveness is interrupted,” means that if he has intercourse with the woman from whom he pronounced zihār, by night or by day, the consecutiveness is interrupted. For example, a man begins fasting the two consecutive months, and after five days have passed he has intercourse with his wife at night. The consecutiveness is then interrupted, and accordingly he must begin again. Even if he had fasted a month and twenty-eight days and then had intercourse with her, he must begin again and fast the two months afresh, because Allah, Most High, says: “Then the fasting of two consecutive months before they touch one another.” [al-Mujādilah 58:4] This is the view adopted by the author.
The correct view, however, is that if he has intercourse with her at night, he is sinful, but the consecutiveness is not interrupted. This is because restarting the two months would not remove either the sin of having intercourse or its harmful consequence. Thus, the one who has intercourse with her at night during the two months should be told: “You have erred and committed a sin, so you must repent; but the consecutiveness is not interrupted.” This is the position of al-Shāfiʿī, the view preferred by Ibn al-Mundhir, and the view regarded as stronger by the author of al-Mughnī.
If he has intercourse with her at night forgetfully, is the consecutiveness interrupted or not? According to the established school, it is interrupted, because the wording is unrestricted. Likewise, if he has intercourse with her while on a journey in which breaking the fast is permitted, it is interrupted. In short, if he has intercourse with the woman from whom he pronounced zihār—even at a time when breaking the fast is permissible, such as at night or during travel that permits breaking the fast, or if he does so forgetfully—the consecutiveness is interrupted. The correct view is that if he has intercourse with her at night, the consecutiveness is not interrupted, though he is sinful; and if he has intercourse with her forgetfully, the consecutiveness is not interrupted and he incurs no sin: it is not interrupted because he did not break his fast, and he incurs no sin because he had forgotten.