The answer is that the Sunnah prescribes this, and that is wisdom enough. Thus, when Aisha, may Allah be pleased with her, was asked, “Why does a menstruating woman make up her missed fasts but not her missed prayers?” she replied: “This would happen to us during the time of the Messenger, peace and blessings be upon him, and we were commanded to make up the fasts, but we were not commanded to make up the prayers.” (1)

Nevertheless, some scholars sought to identify the wisdom behind this (2). Some said: The wisdom lies in making things easier for the legally accountable person, since boys are customarily carried often, rejoiced over, and loved more than girls. Moreover, his urine emerges from a narrow opening and spreads when he urinates; thus, because he is carried frequently and his urine splashes, this would cause hardship, so the ruling was eased in his case.

They also said: His nourishment, which is milk, is light. Hence, once he begins eating food, his urine must be washed; moreover, his digestive power is greater than that of a girl in rendering food light.

The apparent purport of our scholars’ words is that the distinction between the urine of a boy and that of a girl is a matter of ritual observance. (3)

The feces of this boy, like that of anyone else, must be washed.

The urine of a girl, and that of a boy who eats food, are like that of others: both must be washed.

A small amount of impure blood is excused in anything other than a liquid or food …

His statement, “A small amount of impure blood is excused in anything other than a liquid or food,”