If someone is putting on the tefillin shel rosh to adjust the kesher to make sure it fits properly should or can a bracha be made? (Please bring a source either way)?
Answer:
Somebody putting on the tefillin to adjust the knot should not make a berachah. Because he believes the tefillin are not the right size, or at least has a doubt over the matter, he clearly does not have intention to fulfill the mitzvah, and is only trying on the tefillin for size. Mitzvos require intention to fulfill the mitzvah, and therefore under such circumstances (where there is clearly no intention to fulfill the mitzvah) no berachah is made.
