Halakhah su Levitico 15:2

The commandment of the matter of impurity of a zav (one with a discharge) to be impure and to render impure: That a zav be impure and render others impure, as it is stated (Leviticus 15:2-3), "when there be any man with a discharge from his flesh, etc." And the explanation comes, "from his flesh," is meaning a flow from the orifice of the member. And [it is] as they, may their memory be blessed, expounded, "'When there be a discharge' - it is possible, a discharge from any place would be impure. [Hence,] we learn to say, 'from his flesh' and not all of his flesh. Once Scripture has distinguished between flesh and flesh, I have merited to learn out the law of impurity with a zav and with a zavah. Just like a zavah is from the place that she become impure, etc."