Musar for Kiddushin 42:18

There are two kinds of harlots: One is the above mentioned Lilith, who is always associated with wailings and is the power in charge of of melancholy. The other is Machalat who is in charge of the superficial kind of happiness, i.e. dancing, music and generally light-hearted irresponsible conduct inspired by the forces of impurity. Machalat is the mystical dimension of the יפת תואר, the good looking prisoner of war described at the beginning of our פרשה, whose exterior has so captivated a Jewish soldier that he is bent on spending a lifetime with her. The only reason that the Torah gives its reluctant consent to such a marriage is כנגד יצר הרע, as an antidote to the evil urge. The Torah fears that unless a way is found to permit the soldier to live with such a woman under strictly regulated conditions, he would live with her anyway without benefit of marriage. It is not surprising therefore that the children from such a union should fit the category of בנים זרים, alien children, which we have described earlier. This is clearly alluded to by the fact that the Torah's example of a בן סורר ומורה, a rebellious son, is written immediately before the passage dealing with the case of a sinner whose execution results in the posthumous hanging of his body (21,22).