The Torah addresses the case of a thief who cannot repay what he stole. (Exodus 22:3) states: "If he lacks it, he is to be sold for his theft." The thief, unable to make restitution, is sold into servitude to pay his debt. But the Mekhilta DeRabbi Yishmael immediately raises a question: for how long?
Reading the verse in isolation, one might assume the thief is sold permanently — enslaved forever as punishment for his crime. The Mekhilta anticipates this reading and rejects it. The Torah itself provides the answer elsewhere.
In (Exodus 21:2), the Torah states: "Six years shall he serve, and in the seventh he shall go out free." This verse, which appears in the laws governing Hebrew servants, establishes a maximum term of service. The Mekhilta applies it to the thief as well. Even a person sold for theft does not serve indefinitely. He serves for six years and goes free in the seventh.
This legal connection reveals something important about how the Torah views servitude. It is never permanent for a Hebrew. Even when a person's own criminal behavior — his theft, his inability to pay — leads to his being sold, the Torah builds an exit into the system. Six years, no more. The seventh year brings freedom regardless of whether the full debt has been repaid.
The Mekhilta's interpretation ensures that the punishment of being sold for theft is understood as temporary and bounded. The Torah does not create a permanent underclass of debtors. It creates a system of rehabilitation with a fixed end date — and that end date is built into the structure of the Torah itself.