The laws of theft in the Torah are not one-size-fits-all. Different stolen objects carry different penalties, and the Mekhilta works through a particularly tricky case: what happens when someone steals the firstborn of a donkey?
The firstborn donkey occupies an unusual legal category. Under Torah law, the firstborn of a donkey must be redeemed — its owner exchanges it for a sheep, which goes to the Kohen (Numbers 18:15). Until that redemption takes place, the owner cannot derive benefit from the animal. It exists in a state of legal suspension: owned but unusable.
The Mekhilta rules that the thief still pays kefel — double restitution. The reasoning is elegant. Even though the firstborn donkey cannot be used right now, it will become permitted later, once it is properly redeemed. The temporary prohibition on benefit does not erase the animal's underlying value. It is still property worth stealing, and therefore property worth compensating.
The teaching then turns to the broader penalty structure. For stealing an ox, the Torah mandates five-fold restitution. For a sheep, four-fold. The verse spells it out: "Five head of cattle for an ox, and four of the flock for a sheep" (Exodus 21:37). These escalating penalties reflect the animal's economic role — an ox represents a farmer's primary work tool, making its theft especially devastating.
The Mekhilta's analysis demonstrates that Jewish law evaluates theft not just by the act itself but by the nature of what was taken, its current legal status, and its future economic potential.