Sforno on Deuteronomy 23:16/ספורנו על דברים כ״ג:ט״ז

1לא תסגיר עבד אל אדוניו, after the Torah had spoken of the sanctity that must be prevalent in an encampment of Jewish soldiers in war, it switches to matters which are apt to happen in such surroundings, explaining how to correct deviations. One of these is how to deal with a gentile slave who has escaped from his master and taken asylum among the Jewish people; another is the subject of loose women who have infiltrated into the encampment of the Jewish army, an everyday occurrence in gentile armies. (verse 18)