Q. (See question 2151) If one does perform a mitzvah by just sitting in a shul or beis medresh, would it be commendable to hold a lecture on health issues or other community needed or educational topics inside them?
A. Bnei Tzion (151: 11) quoting Talmud (Shabbos150a) maintains that it is permitted to assemble in a shul in order to deal with the communal needs.
S’ridei Eish (12) further allows in need, to use a shul for lectures that involve health, welfare and similar issues that are for the benefit of the congregation.
However, Horav Shlomo Miller’s Shlit’a opinion is that it is better to abstain from delivering those lectures in the shul or bais hamedresh itself, since it lowers and derides the sanctity of a place dedicated to Torah and tefilah.
Preferably an adjacent area should be used.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a