The 141st mitzvah is that we are commanded to cancel during the shemittah year all debts that we are owed.
The source of this commandment is G‑d's statement,1 "If you have any claim against your brother for a debt, you must relinquish it." This commandment is repeated in the verse,2 "The idea of the shemittah year is that every creditor shall remit any debt [owed by his neighbor]."
The Tosefta says: "Scripture speaks of two types of shemittah (release) — one regarding land and one regarding money."
The mitzvah of releasing debts is only a Biblical commandment when the mitzvah of shemittah of the land is in effect — at which time it applies everywhere.3
The details of this mitzvah are explained in the last chapter of tractate Sh'vi'is.
