And this is the manner of the release: every creditor shall release that which he has lent to his neighbor; he shall not exact it of his neighbor and his brother, because the release of Hashem has been proclaimed.
English: "He shall not exact" — The Sages taught: One who lends money to a kohen, a Levi or a poor person on the understanding that he will separate their portions [of terumah or ma’aser] on their behalf—the seventh year does not cancel the debt, because the verse "he shall not exact" does not apply to him.
On the daf / in context: When the loan is structured so that repayment will come through the sacred gifts themselves, the relationship is not that of an ordinary creditor who "exactes."
Type of Learning
Derash on the verse (Gittin) — certain conditional loans to the poor or Levi are not cancelled.
What Is Learned
A loan made to a kohen, Levi or poor person against future terumah or ma’aser is not cancelled by shemittah.