Purim And Sh’mittah

Mordechai from Givat Sha’ul asks:

Since Purim is approaching, I would like to know if I may
send sh’mittah wine and fruit for mishloach monos.

It is forbidden to repay a debt using sh’mittah
produce (Tractate Avoda Zoro 62a). The Torah stipulates that sh’mittah
produce is meant to be eaten—and not to be traded in. Paying a debt is a form
of trade, produce being substituted for money. It would therefore seem that to
use it to repay a debt would be a violation of a Torah prohibition, this being
the view of the Ramban and the Ritvo. However, the Chazon Ish
(13:26) writes that the prohibition is rabbinic (one is not benefiting from sh’mittah
produce in the usual manner). The Rambam (6:10) writes that even to pay a
preexisting obligation to charity is included in this prohibition. On the other
hand, one may give a gift of sh’mittah produce since this is not
considered a form of trade (Sefer HaShmittah 8:1:9). Since the mitzvah
of mishloach monos is to send gifts to others, there should be no problem
in using sh’mittah produce. Nevertheless, the Steipler Gaon used to
fulfill his basic obligation (the first set of two gifts) with non-sh’mittah
produce.