The Gemara concludes that the halacha
regarding Shemini Atzeres is meisav yasvinan
beruchei lo mevarchinan, we dwell in the
Sukkah but we do not recite a blessing for the
mitzvah of dwelling in the Sukkah. The
Medrash states that the reason why we
celebrate Shemini Atzeres is because HaShem
declares, “you, the Jewish People have been
with Me now for seven days. It is very difficult
to have you part from Me. Please, stay with
me another day.” We find that the word
yeshiva in certain contexts means to tarry or
to remain behind. Perhaps the Gemara is
alluding to this idea that we tarry in the
Sukkah because it is difficult for HaShem that
we leave Him, but we do not recite a blessing,
because HaShem has never left us.