Why is Baruch Hashem L'olam said on Motzei Shabbos V'Yom Tov in Nussach Ashkenaz?
A priori question: Why do some congregations say Baruch Hashem L'Olam (BHL) at all?
The 2 possible answers I'd seen/heard previously:
- Shuls were outside of towns and people were afraid to spend so long after dark away from the town. To reduce this time, it was instituted to say BHL in lieu of Amidah.
- Similarly, the shuls were far away from people working in the fields and it would be dangerous for latecomers to remain alone. To allow them to catch up, BHL was added.
Based on this, we can understand why BHL wasn't said on Shabbos or Yom Tov - more people gathering and less time spent working Erev Shabbos/Yom Tov in general meant it wasn't necessary.
However, on Motzei Shabbos/Yom Tov, some congregations still say it, even though the same situation should occur - namely that the people have all been in Shul for Mincha and are still gathered together for Maariv. Why then do we say it on Motzei Shabbos and Yom Tov?