At the end of every seven years thou shalt make a release. And this is the manner of the release: every creditor shall release that which he hath lent unto his neighbour; he shall not exact it of his neighbour and his brother; because the LORD’S release hath been proclaimed. … whatsoever of thine is with thy brother thy hand shall release. …
Beware that there be not a base thought in thy heart, saying: ‘The seventh year, the year of release, is at hand’; and thine eye be evil against thy needy brother, and thou give him nought; and he cry unto the LORD against thee, and it be sin in thee. Thou shalt surely give him, and thy heart shall not be grieved when thou givest unto him. (Deuteronomy 15:1–10)

מִקֵּץ שֶׁבַע שָׁנִים תַּעֲשֶׂה שְׁמִטָּה. וְזֶה דְּבַר הַשְּׁמִטָּה: שָׁמוֹט כָּל בַּעַל מַשֵּׁה יָדוֹ אֲשֶׁר יַשֶּׁה בְּרֵעֵהוּ. לֹא יִגֹּשׂ אֶת רֵעֵהוּ וְאֶת אָחִיו – כִּי קָרָא שְׁמִטָּה לַה' … וַאֲשֶׁר יִהְיֶה לְךָ אֶת אָחִיךָ – תַּשְׁמֵט יָדֶךָ ...
הִשָּׁמֶר לְךָ פֶּן יִהְיֶה דָבָר עִם לְבָבְךָ בְלִיַּעַל לֵאמֹר: קָרְבָה שְׁנַת הַשֶּׁבַע שְׁנַת הַשְּׁמִטָּה, וְרָעָה עֵינְךָ בְּאָחִיךָ הָאֶבְיוֹן וְלֹא תִתֵּן לוֹ – וְקָרָא עָלֶיךָ אֶל ה' וְהָיָה בְךָ חֵטְא. נָתוֹן תִּתֵּן לוֹ, וְלֹא יֵרַע לְבָבְךָ בְּתִתְּךָ לוֹ. (דברים ט"ו, א-י)

The Sages understood Deuteronomy’s release law as requiring complete cancellation of debt on a particular day at the sabbatical year’s beginning or end. Apparently, however, the verses discuss neither cancellation nor a specific date, as one would expect for cancellation, but a prohibition on forcibly demanding payment throughout the year: “he shall not exact it of his neighbour and his brother.” In the plain meaning, debts are not canceled at a point during the year; collection is suspended throughout it to ease the poor’s situation, like ceasing fieldwork in the seventh year and work on the seventh day, mentioned together in Exodus 23:10–12.

Why did the Sages prefer cancellation to the more literal prohibition on collecting during that year?

They apparently saw Deuteronomy’s debt release as additional to Exodus’ land release, both applying simultaneously. This makes a prohibition on collection during the year difficult: land release actually improves the poor’s relative situation, allowing free gathering of grain and produce. The economic problem, chiefly affecting the poor, begins afterward, when the cultivation ban leads to agricultural shortages and higher prices in the following year.

If the Torah aims to ease the poor’s situation by temporarily postponing repayment, as the plain meaning suggests, postponement should occur after the sabbatical year, when shortages and distress increase, rather than during it. The Sages therefore preferred complete cancellation, producing significant relief continuing beyond that year.

In the plain meaning, however, Deuteronomy’s debt release seems to replace land release rather than supplement it. Its release verses ignore land release altogether.

Moreover, their wording hints at changing or revising the familiar law. The opening is general: “At the end of every seven years thou shalt make a release.” But instead of immediately detailing its rules, the text qualifies: “And this is the manner of the release,” as if saying: not the release you knew, but a different kind.

This wording is familiar from accidental killing: “that every manslayer may flee thither,” immediately narrowed to “And this is the case of the manslayer … whoso killeth his neighbour unawares,” meaning only an accidental killer. Likewise here: not release of land, but of debt.

Debt release thus stands independently of agricultural release. It is therefore logical to set cancellation of debts specifically in the sabbatical year, giving borrowers and the poor a year of economic rest and peace from creditors.