until it goes beyond fifteen days. Such a woman menstruating for the first time has no prior established cycle to which she can refer. With regard to irregular bleeding, she therefore has only two recourses:

First: discernment, which is a specific indicator.

Second: the usual cycle of most women in her family, which is a general indicator. The specific takes precedence over the general. Irregular bleeding is the flow of blood from a vein in the lower part of the uterus called al-ʿādhil.

For example, if she were to sustain a wound in a vein and blood continued to flow, this would not be normal; rather, it would be an illness caused by the rupture of one of the veins in the lower part of the uterus.

Menstruation, on the other hand, is the flow of blood from a vein at the base of the uterus called al-ʿādhir.

The author—may Allah have mercy on him—then explained discernment, saying: “If some of her blood is red and some of it is black.” This is one of the indicators of discernment, so she is told: refer to discernment.

Discernment means distinguishing in order to determine whether the blood is menstrual blood or irregular bleeding.

The author mentioned one indicator, namely color. Discernment has four indicators:

First: color. Menstrual blood is black, whereas irregular bleeding is red.

Second: consistency. Menstrual blood is thick and heavy, whereas irregular bleeding is thin.

Third: odor. Menstrual blood has an offensive, unpleasant smell, whereas irregular bleeding has no offensive odor, because it is ordinary venous blood.