cessation is sufficient for purification and prayer, her purification is invalidated by the return of the blood; because by this cessation, she has entered into the status of those who are pure, so the return of the blood is like the occurrence of a hadath. If it is a cessation that is not sufficient for that, its return has no effect; because she is a mustahada, and this cessation has no ruling. This is the school of al-Shafi'i. We have already mentioned from the words of Ahmad, may Allah have mercy on him, what indicates that this cessation is of no account. Rather, whenever she is a mustahada or has an excuse from among these excuses, and she takes precautions and purifies herself, then her purification is valid, and her prayer performed with it is binding, as long as her excuse does not cease, she does not recover from her illness, the time of the prayer does not expire, or she does not commit a hadath other than her [primary] hadath.

Section: If she has a habit of the blood ceasing for a duration not sufficient for purification and prayer, and she performs ablution, then her blood ceases, it shall not be ruled that her purification or her prayer is invalid if she is in the midst of it; because this cessation does not fulfill the intended purpose. If the cessation continues and she recovers, and blood had flowed from her after the ablution, the purification (17) and the prayer are invalidated; because we have determined that she entered into the status of those who are pure by that cessation. If it ceases (18) for a duration sufficient for purification and prayer, then the ruling for her is the same as the ruling for one who does not have a habit of its cessation, based on what was mentioned regarding it. If she has a habit of it ceasing for a duration sufficient for purification and prayer, she shall not pray while the blood is flowing and shall wait for it to stop, unless she fears the expiration of the time, in which case she performs ablution and prays. If she begins the prayer at the end of the time with this purification, and the blood stops for her, her purification is invalidated; because it was possible for her to pray with a purification that was not necessary, so her prayer is not valid without it, just like someone who is not a mustahada. If the duration of its stopping varies, sometimes being sufficient and sometimes not, she is like the one before her, unless she knows that its cessation at this time is not sufficient. It is possible that if she begins the prayer and then the blood ceases, her prayer does not become invalid; because she began it with a certain purification, and it is possible that the cessation of the blood might be of a sufficient duration, in which case it is invalidated, and it is possible that it might be of a short duration, so it [does not become invalid, nor does] (19)