הלכה על גיטין 71:14

That he release all of his loans in the seventh [year]: To abandon all of his debts on the sabbatical year. And about this is it stated (Deuteronomy 15:3), "and that which you have with your brother, release your hand." And the warning is repeated about this commandment, as it is stated (Deuteronomy 15:2), "And this is the matter of the sabbatical year, every owner of a debt shall release his hand." And they said in the Tosefta (brought in Gittin 36a), "The verse is speaking about two releases: one is the release of land and [the other] is release of monies."