And when he indicated that spending money in its proper way is purity, and that withholding it from that is a waste, he followed it with a gesture indicating that spending the private parts in other than their proper way is impurity, and preserving them is purity. So he said: "And those who are guardians of their private parts" in sexual intercourse and what is close to it, both outwardly and inwardly, "are always guarding them" meaning they do not follow their desires, rather they are standing over them, humbling them and controlling them. And mentioning it after the idle talk that calls to it and spending money, which is one of the greatest causes of it, is of great relevance.