The Mekhilta draws a careful legal distinction between two cases that the Torah addresses separately: the ravished girl and the enticed girl. The difference between these two situations has significant implications for the financial penalty — the knass — that the perpetrator must pay.
In the case of a ravished girl, the man violates two wills simultaneously: the will of the girl herself, who did not consent, and the will of her father, whose authority over his daughter's marriage prospects has been violated. The offense is double — both the victim and her father have been wronged.
In the case of an enticed girl, however, the situation is different. The girl participated willingly, so her own will was not violated. Only the father's will was transgressed, since his daughter entered a relationship without his consent or knowledge. Here, only one party — the father — has been wronged.
Given this distinction, one might logically argue that the enticed girl's case should carry a lesser penalty. If the knass is imposed in the ravishment case because two wills were violated, then perhaps when only one will is violated, the fine should not apply at all. The reasoning seems sound.
But the Mekhilta concludes that this logical argument, however reasonable, is insufficient. The law cannot be derived by reason alone in this instance. Instead, an explicit verse must be cited to establish that the knass applies in both cases. When logic falls short, the Torah's own words fill the gap — a reminder that rabbinic jurisprudence always returns to the text as its ultimate authority.