Or HaChaim on Leviticus 25:28/אור החיים על ויקרא כ״ה:כ״ח

1 ואם לא מצאו ידו די השיב, "But if he does not have sufficient means to restore it to himself, etc." If G'd observes that the people do not possess the strength to endure all the suffering that is their lot, and the debt they owe is still great, והיה ממכרו עד שנת היובל, "then its sale will extend (only) to the Jubilee year, etc." Here the Torah refers to G'd's timetable, i.e. the ultimate date for the eventual redemption. At that time, ויצא ביובל ושב לאחוזתו, He will come out in the Jubilee year and return to His heritage (rebuild the Temple). Exile will come to an end even if the Israelites will be (G'd forbid) absolute sinners.