[Avodah] When Shabbos is Motzaei Rosh Chodesh

[Akiva Miller]

.
R' Akiva Blum wrote:
> Please see the Mishna Berurah 188:32 where he quotes the
> Acharonim that if during Seuda Shelishis someone davened
> maariv, he can no longer say retzei.

And R' Joel Rich asked:
> I wonder if he meant maariv literally or if one had intent
> and said atah chonentanu as havdalah - since in theory you
> can daven maariv after plag - would he say if you did that
> you don't say retzeih if you ate later?

This situation is raised by Rabbi Simcha Bunim Cohen in "The Radiance
of Shabbos" (ArtScroll). He writes (pg 95?), "If one interrupts a
prolonged meal to daven Maariv or recite Havdalah, he does not say
Retzeh in Bircas Hamazon afterwards. If one merely said Baruch
Hamavdil Bein Kodesh L'chol, he should still recite Retzeh in Bircas
Hamazon.

Rabbi Cohen cites MB 263:67 that if one said "Hamavdil Bein Kodesh
L'chol" during the meal, it is a "Tzorech Iyun" whether he can say
Retzeh. Then he cites Eliya Rabba 299:1, Petach Hadvir there, Chayei
Adam 47:24, Kaf Hachayim Palagi 31, and Rav Moshe Feinstein all as
saying that one *can* still say Retzeh, but that Shulchan Aruch Harav
188:17 says not to.

Personally, I am surprised that so many poskim distinguish between
Maariv/Havdala on the one hand, vs. Omitting Shem Umalchus on the
other hard. Here is a situation which will illustrate this point:
Suppose someone had a long seuda shlishis, and after Tzeis he said
Baruch Hamavdil Bein Kodesh L'chol, and then he actually did a
melacha. Would those poskim still say that he should recite Retzeh in
Bircas Hamazon?

Akiva Miller