Chapter on the Rules of Menstruation, Istihadah, and Nifas, and Purification From Them

The statement "she adds a precautionary day or two" applies when her usual menstruation lasts less than ten days. In this case, she adds one or two days as a precaution. However, if her regular cycle is ten days, she does not add any extra days, and the rules of istihadha apply to her as described earlier. Similarly, any narrations that mention adding a precautionary day or two, or even three, follow the same principle and are applied according to the specific case of the woman’s menstrual habits.