במדבר, פרק ל״א, פסוק י״ח

Following the victory over Midian, a sharp line is drawn to determine the fate of the captive women, separating the guilty from the innocent. The young girls are spared because they alone had no part in causing the Israelites to sin [ביאור שטיינזלץ]. The older women had been forced into prostitution by their husbands and fathers as part of Balaam's plot, and therefore faced punishment, leaving only the young girls to be saved [הכתב והקבלה]. A strict standard is applied to the captives: any woman or girl who had experienced intimate relations, even through forced prostitution, is deemed unfit to join the Israelite nation [העמק דבר, מלבי״ם].

The decision to spare these young girls carries a few complementary meanings. At a basic level, they are kept alive to serve the Israelites as captives and maidservants [ביאור שטיינזלץ, תורה תמימה על התורה, הכתב והקבלה]. However, other commentators see this as an opportunity for the girls to fully integrate into the nation. In this view, keeping them alive actually refers to converting them, as the act of conversion is viewed as granting new life. This spiritual renewal makes them eligible to marry any Israelite man who wishes to take them as a wife [אור החיים, העמק דבר].

This potential for marriage sparks a legal debate specifically concerning the priests. Because Phinehas the priest was present at the battle and received these instructions, Rabbi Shimon bar Yochai concludes that a female convert who joins the faith before the age of three is permitted to marry a priest [חזקוני, מלבי״ם, תורה תמימה על התורה]. The Sages, however, disagree. They rule that a female convert is always forbidden to marry a priest due to the lingering concern of past prostitution. According to their view, the priests are only allowed to take these girls as maidservants, while the rest of the Israelites are entirely free to marry them [תורה תמימה על התורה, הכתב והקבלה].