"You shall not steal" — this is the eighth of the Ten Commandments. But what kind of stealing does it prohibit? The Mekhilta argues it refers to kidnapping, not theft of property.
The reasoning begins with a problem. (Leviticus 19:4) already says "You shall not steal and you shall not deal falsely" — and that verse clearly addresses stealing money and property. If the prohibition against property theft is already covered elsewhere, the version in the Ten Commandments must address a different kind of stealing entirely.
The Mekhilta concludes that "You shall not steal" in the Decalogue is an exhortation against stealing souls — kidnapping a human being. This interpretation is reinforced by context. The commandment appears between "You shall not murder" and "You shall not commit adultery" — both of which are capital offenses. It would make sense for the prohibition sandwiched between them to also carry the death penalty, which kidnapping does (Exodus 21:16) while ordinary theft does not.
This reading has profound implications for how Jews understand the Ten Commandments. The eighth commandment is not about shoplifting or embezzlement. It is about the most extreme violation of another person's autonomy — seizing a human being and treating them as property. The commandments move from murder (destroying a life) to kidnapping (stealing a life) to adultery (stealing a relationship). Each one addresses a different dimension of the ultimate crime: treating persons as things.