Negative commandment · Lo Ta’aseh #230 of 613
Not to demand the repayment of a loan after the seventh year has passed
שלא יתבע הלוואה שעברה עליה שביעית
The verse · Devarim 15:2
וְזֶה דְּבַר הַשְּׁמִטָּה שָׁמוֹט כׇּל־בַּעַל מַשֵּׁה יָדוֹ אֲשֶׁר יַשֶּׁה בְּרֵעֵהוּ לֹא־יִגֹּשׂ אֶת־רֵעֵהוּ וְאֶת־אָחִיו כִּי־קָרָא שְׁמִטָּה לַה׳
“And this is the manner of the release: every creditor that lends anything to his neighbour shall release it: he shall not exact it of his neighbour, or of his brother; because he has proclaimed a release to the Lord.”
The Rambam’s words
Not to demand the repayment of a loan after the seventh year has passed, as [Deuteronomy 15:2] states: "Do not demand payment from your fellow man."
שלא יתבע הלוואה שעברה עליה שביעית, שנאמר "לא ייגוש את ריעהו ואת אחיו" (דברים טו,ב).
Where in the Mishneh Torah
Hilchot Sabbatical Year and the Jubilee הלכות שמיטה ויובל