Rebbi, the great Rabbi Yehudah HaNasi, offered a precise definition of a word that usually sounds limitless. When the Torah says a Hebrew servant "shall serve him forever" (Exodus 21:6), what does "forever" actually mean? Rebbi's answer: fifty years.
The proof comes from the institution of the Yovel, the Jubilee year, which occurs every fifty years. In the Jubilee, all Hebrew servants go free, all ancestral lands return to their original owners, and debts are released. The Torah commands freedom "forever," but the Jubilee trumps that forever. When the fiftieth year arrives, the servant walks free regardless of any prior arrangement.
Rebbi then adds a second condition. The servant also goes free upon the death of his master. So "forever" in this context means whichever comes first: the Jubilee or the master's death. It emphatically does not mean what the English word "forever" implies, an endless, permanent state.
This teaching reveals something fundamental about how the rabbis read the Torah. Words in Scripture do not always carry their plain meaning. "Forever" can mean fifty years. "Day" can mean an era. The Torah uses expansive language that the Oral Tradition then defines and constrains. Without the rabbinic interpretation, one might read (Exodus 21:6) as sanctioning permanent, lifelong slavery. The Mekhilta ensures that reading is impossible. Hebrew servitude has a built-in expiration date, a maximum of fifty years, because in God's legal system, no human being can belong to another human being in perpetuity.