After so much debate as to when and under what conditions one may or may not interrupt during Shema - how does the Mishna Berurah ignore it all to say, in effect, "nowadays it is our custom not to interrupt . . ."
What is his source? How did the custom come about?
Joe Schwarz, New york, NY USA
The Poskim were concerned with Amei ha'Aretz, those ignorant in Halachic matters, who would not know how to differentiate between an interruption for the sake of giving honor or showing reverence, and an interruption for a trivial matter. We find a similar concept in Shabbos 139b, as Tosfos there mentions in the name of Rabeinu Tam.
(We apologize for the four month delay on getting back to your question!)