After the seventh in a series of Shemitta cycles, Bnei Yisrael, in the time that “all its inhabitants” are in Eretz Yisrael, are commanded in the laws of Yovel (Vayikra 25:8-13). There are three main halachot: Jewish slaves are set free (ibid. 10); the land is not worked, as in the previous Shemitta year (ibid. 11); fields that were sold are returned to their original owner (ibid. 13).
“If you follow my statutes … I will send rain in its time… and you will live securely in the Land” (Vayikra 26:3-5). The Midrash commenting on this pasuk explains that fulfilling the statutes brings a person to the World to Come. The pasuk (Yeshayahu 4:3) states: “Those who remain in Zion and are left in Jerusalem, all who are inscribed for life in Jerusalem shall be called holy.” This refers to one who delves into Torah, which is the tree of life as it says: “It is the tree of life for those who cleave to it” (Mishlei 3:18). Rav Elazar commented: The sword and the book were given wrapped together from Heaven. Hashem said: “If you keep what is written in this book, you will be spared from the sword, but if not, you will be killed.” This is learned from: “He drove man out and stationed the cherubim east of the Garden of Eden, the fiery ever turning sword, to guard the way to the tree of life” (Bereishit 3:24). The way refers to derech eretz and the tree refers to Torah (Vayikra Raba, 35:6).
In explaining the mitzva of yovel, the Torah says that the Land will not be sold for eternity and finishes up that this is related to the concept that we are “foreigners and citizens with Me” (Vayikra 25:23). The connection to “with Me” appears to be as follows: If you treat Me like one who fully belongs, then you fully belong; if you treat Me as an outsider, you too will be like outsiders.
“I loaned someone money, and I did not hassle him for payment when he told me that things were tough. Recently, I contacted him to ask if he is in any position to pay back. He replied that he was forced into bankruptcy and thereby absolved all his debts. Does he, indeed, no longer owe me for the loan?
The rationale behind Shmita, is to create for us a “Shabbat Shabbaton” every 7 years. Like the contemporary Sabbatical, this results in a complete change in our routine, a break from the norm, a chance to recharge the batteries & then make a new start, refreshed & reinvigorated.