The Torah states: "And if a man sells his daughter" (Exodus 21:7). The Mekhilta immediately draws attention to a legal distinction embedded in this verse that might otherwise go unnoticed. A father may sell his daughter into servitude, but he may not sell his son. The verse specifies "his daughter" deliberately, and the exclusion of sons is the entire point.
At first glance, this seems counterintuitive. The Mekhilta walks through the logical argument that would lead someone to the opposite conclusion. A daughter, when she grows up, cannot be sold by the court (beth din) for theft. An adult woman who steals is never sold into servitude as punishment. An adult son, by contrast, can be sold by the court for theft if he cannot repay what he stole. So if a father can sell the person who enjoys greater legal protection as an adult (the daughter), surely he should also be able to sell the person who has less protection (the son)?
The logic seems airtight. If the more protected category can be sold by a father, the less protected category should certainly be sellable too. But the Torah blocks this inference with its precise wording. "If a man sells his daughter" — his daughter and no one else. The verse limits the father's power of sale to daughters exclusively.
This passage demonstrates a core principle of rabbinic legal reasoning. Human logic, no matter how compelling, cannot override the plain text of Scripture. The kal va-chomer argument (reasoning from lighter to heavier) would naturally extend the father's selling power to sons. But the Torah's explicit limitation to daughters closes that door. When Scripture speaks specifically, no logical inference can expand the law beyond what the text says.