Configuring Parashas Zachor and Purim Meshulash 5781
As detailed at length in a popular multi-part series earlier this year, titled “5781 – An Exceptional Year” [see here: and here:], 5781 is a year that is chock-full of rare calendarical occurrences that we are taking an active part in. Although the series delineated many fascinating phenomena, this article focuses on several important ones starting this Shabbos. And so, after considerable research into their ramifications, we now continue our halachic trek through this remarkable year…
The Arba Parshiyos Puzzle
Moving along into the “simchah season” known as the joyous month of Adar, it is well known that many changes were instituted to the normal weekly Torah readings, in the Maftir and Haftarah, each for their own purpose and reason, and this year is no exception.
First up is Parashas Shekalim, on the Shabbos beforeor of Rosh Chodosh Adar(read last Shabbos), which commemorates the communal mitzvah of the giving the Machtzis Hashekel, used to pay for the daily Korban Tamid for the whole year.
Next is Parashas Zachor, which is always read on the Shabbos before Purim, as it evokes and condemns the unprovoked attacks of the evil Amalek on Klal Yisrael, paralleling and foreshadowing the genocidal plot of his wicked descendant, Haman, detailed in Megillas Esther, which is read on Purim.
Third is Parashas Parah, on the third week of Adar, commemoratingthe Parah Adumah (Red Heifer) used to purify Klal Yisrael for the upcoming Korban Pesach.
Lastly, on the Shabbos before or of Rosh Chodesh Nisan, is Parashas Hachodesh, to properly honor the coming of the “First Month” that we were commandedin the Torah to observe, Rosh Chodesh Nisan. These four changes to the Maftir and Haftarah are collectively known as the “Arba Parshiyos”.
The Gemara in Megillah (29a - 30b) devotes considerable attention to the details of the “Arba Parshiyos”, including how to compute the Jewish calendar’s nineteen year cycle of which exact week will host which special reading. It seems a bit confusing, but luckily several of our great early authorities, including the Rif, Rashi, and the Rosh, give a simple mnemonic that allows anyone to figure out which week is which. This is especially practical for a shul’s gabbai who has to arrange the Sifrei Torah to the properplaces on each of these weeks. In fact, this code is so useful that it is even cited as halacha by the Tur and Shulchan Aruch.
ZAVD”U- זבד"ו- Unlocking the Code
In our Jewish calendar, the second day of Rosh Chodesh Adar, meaning the first actual day of the month of Adar (in leap years this is referring to Adar Sheini), can only fall out on four days of the week - Shabbos, Monday, Wednesday, and Friday.
The mnemonic for these days that Rosh Chodesh Adar can occur on is ZAVD”U. This stands for Zayin, the seventh day of the week - Shabbos, Beis stands for the second day of the week - Monday, Dalet refers to the fourth dayof the week - Wednesday, and Vav the sixth day of the week – Friday.
The Rishonim teach us that each of theseletters stands for an additional code: ZAT”U, B”O, DA”D, U”BIV (or U”BYU); and knowing their meanings will help us calculate which week each of the Parshiyos will fall out on. The first letter of each of these codes refers to which day of the week Rosh Chodesh Adar falls out on, and the remaining letters refer to which day(s) of the week during the month is a “skip week”, with no special reading.
ZAT”U refers to when Rosh Chodesh Adar fallsout on a Shabbos (“Zayin”, the seventh day of the week), then that day itself - Shabbos (the first week), Parashas Shekalim is read, the subsequent Shabbos is Parashas Zachor, the next Shabbos - “TU” or the fifteenth of Adar - is a “skip week” with no exceptional attributes, the following Shabbos is Parashas Parah, and the last one is Parashas Hachodesh. This breakdown of the code applies for all the rest as well. This year, 5781 is classified as a rare ZAT”U year, with Rosh Chodesh Adar falling out on Friday-Shabbos.
Zachor – Terumah and Three Torah Mishpatim
This setup creates an interesting calendarical anomaly, albeit one with absolutely no halachic significance. You see, this causes Parashas Zachor to be preempted and read on an earlier Parashah than is typical. Usually, in a non-leap year, Parashas Zachor is read on Parashas Tetzaveh. Yet, this year, it will be pre-empted a week, and read on Parashas Terumah. This also put Parashas Shekalim, in this instance a week prior, leined on Parashas Mishpatim. Although Mishpatim is often Parashas Shekalim, nonetheless, this year it was also Shabbos Rosh Chodesh, and hence Mishpatim ended up being a Three-Torah Parashah; also a rarity. Both of these last occurred twenty years ago in 5761.
Purim Shechal B’Erev Shabbos
As we are already discussing the Purim season, the next calendar quirk has significant importance. You see, in 5781, if 1 Adar was on Shabbos, then Purim, fourteen day later will fall out on Friday. For most of us worldwide this will mean a rushed day to pack in all of the Purim-day Mitzvos before the onset Shabbos. Indeed, the Rema writes that on a Purim Shechal B’Erev Shabbos, we should start the Purim Seudah before Chatzos – halachic high noon. However, if that is not feasible, the Mishnah Berurah cites the Yad Efraim quoting the Maharil, that in this situation; one has a bit more time to start his Purim Seudah - until the beginning of the tenth hour - three halachic hours before shkiya. This is due to the halacha that one may not eat a Seudas Keva – a set meal within three halachic hours prior to the onset of Shabbos, as this will impugn Kavod Shabbos.
Yet, it is important to note that if one was unable to start his Seudah before the tenth hour on this Erev Shabbos Purim, he should still eat his Purim Seudah then since it is considered a “Mitzvah B’Shaatah,” A Mitzvah in its proper time, which although not optimal at that specific time, nevertheless trumps the prohibition of not starting a Seudah within three halachic hours of Shabbos. However, one should not stuff himself at this Seudah and minimize bread consumption, in order to save some room for the upcoming Seudas Shabbos.
Yet, for those fortunate enough to live in Yerushalayim (or other walled cities from the time of Yehoshua Bin Nun) where Purim is celebrated on the next day, Shushan Purim, which falls out on Shabbos, this unique set of circumstances triggers the incrediblePurimMeshulash,or “Triple Purim,” a rare three-day Purim extravaganza. Thislast occurred back in 5768/2008, and prior to that in 5765/2005 and 5761/2001, and is next expected in another four years in 5785/2025, followed by a long break of 20 years, in 5805/2045, and then three years later in 5808/2048.
This rare occurrence is due to the same Gezeiras Chazal regarding Shofar and Lulav, that due to the Megillah obligation, one may unwittingly carry it on Shabbos outside the permitted Reshus to an expert. Hence, the Megillah may not be read on Shabbos; ergo, Purim’s Mitzvos get divvied up to the surrounding days.
It is important to note that this three-day Purim Meshulash is not an actual three-day Yom Tov. Each separate day possesses unique observances of Purimexclusive to it, with the different Mitzvos of Purim applying separately on Friday, Shabbos, and Sunday. Friday’s Mitzvos are the Megillah reading and Matanos L’Evyonim- following the rest of the world.
Shabbos, the actual day of Shushan Purim, has the recitation of Al Hanissim and the special Purim Maftir(“Vayavo Amalek”), as well as the haftarah of Parashas Zachor (“Pakaditi”) read a second time (two weeks in a row!), and a special inyan to learn Hilchos Purim. Sunday’s Mitzvos are Mishloach Manos and the Purim Seudah. However, and although not the actual halacha (and discussed extensively in the footnotes), there are shittos who are of the opinion that due to various machlokesim it is preferable to give Mishloach Manos on two or even all three of the days of Purim Meshulash, as well as having an extra Purim Seudah (or at least extra foods) on Shabbos Purim.
Yes, as one who has celebrated a few over the years, there is nothing quite like the incredible joy of a Purim Meshulash. An exceptional holiday for an exceptional year.
This article was written L’Iluy Nishmas Shoshana Leah bas Dreiza Liba and l’zechus for Shira Yaffa bas Rochel Miriam v’chol yotzei chalatzeha for a yeshua sheleimah teikif u’miyad!
For any questions, comments or for the full Mareh Mekomos / sources, please email the author: email@example.com.
Rabbi Yehuda Spitz, author ofM’Shulchan Yehuda on Inyanei Halacha, serves as the Sho’el U’Meishiv and Rosh Chabura of the Ohr Lagolah Halacha Kollel at Yeshivas Ohr Somayach in Yerushalayim.
His first English halacha sefer, “Insights Into Halacha: Sefer Iyunim B’Halacha: Hilchos Hamazon – Food: A Halachic Analysis,” focusing on the myriad halachos related to food, is now available through the author and Jewish bookstores worldwide. Click here for details:
 “Mishenichnas Adar Marbin B’Simchah” (Gemara Taanis 29a).
See at length Gemara Megillah (29a-30b). For a brief summary of the Gemara’s conclusion see Mishnah Berurah (685:1).
“Hachodesh Hazeh Lachem Rosh Chadashim, Rishon Hu Lachem Lechadshei Hashana” (Parashas Bo, Shemos Ch. 12: 2). Everyone knows the famous Rashi on the very first pasuk of the Torah citing Rabbi Yitzchak [see Sifsei Chachamim and the Taz’s Divrei Dovid ad loc. as to the identity of this Rabbi Yitzchak, whether referring to Rashi’s father or the Amora; see also Bereishis Rabba (Ch. 1:2) and Midrash Tanchuma Hayashan, (Bereishis 11)], that the Torah could have started with this pasuk, as it was the very first Mitzvah given to Klal Yisrael as a nation.
Our set calendar was established millennia ago by Hillel II. Also known as Hillel Nesiah, he was a 13th or 14th generation descendent of Hillel I (Hillel Hazakein). See Ra’ah (Beitzah 4b) and Sefer Hachinuch (Parashas Bo, Mitzvah 4 – Kiddush Hachodesh; see also Machon Yerushalayim’s edition of Minchas Chinuch ad loc. footnote 11, that states that the calendar’s establishment transpired in the generation after Abaye and Rava).
Rif (Megillah 10b), Rashi (Megillah 30b s.v. v’ee), Rosh (Megillah Ch. 4, 10, end s.v. Yerushalmi), Tur and Shulchan Aruch (O.C. 685:6).
This is basic Gematria. Each of the letters of the Hebrew Aleph-Beis has an equivalent numerical value. For example, Aleph equals one, Beis equals two, Dalet equals four, Vav equals six, Zayin equals seven, etc. Hence, Beis, which equals two, refers to the second day of the week, Monday. Dalet, which equals four, refers to the fourth day of the week, Wednesday, etc.
Except of course for those fortunate enough to live in Yerushalayim (or other walled cities from the time of Yehoshua Bin Nun), for that skip week is actually Purim Meshulash, a rare three-day Purim extravaganza, with the different mitzvos of Purim applying separately on Friday, Shabbos, and Sunday. This will be detailed at length shortly.
One Torah for Parashas Mishpatim, one for Shabbos Rosh Chodesh, and one for Parashas Shekalim. See Orach Chaim (685:1); based on Gemara Megillah (29b).
I used the expression “most of us,” as there will undoubtedly be minority who will attempt to take advantage and perform the halachically not-so-simple “Pores Mapah U’Mekadeish” to extend their Purim Seudah into their Leil Shabbos Seudah (as per Gemara Pesachim 105a-b). See Magen Avraham (O.C. 695:9; citing theMordechai), Chayei Adam (vol. 2:155, 32),and Mishnah Berurah (ad loc. 15; see also O.C. 271:4 and 6). If one performs this properly he is considered to have fulfilled his obligations of both the Purim Seudah and Shabbos Seudah (see Kovetz Teshuvos vol. 2:17). Both the Meiri (Kesuvos 7b) and the Maharikash (Erech Lechem O.C. 695) wrote that they personally did this on Purim Erev Shabbos, as opposed to the Maharil (56; who seems not to have accepted this) and the Leket Yosher (pg. 156; who wrote “ain nohagin lekadeish”); see alsoHalichos Even Yisrael(Moadim vol. 2, pg. 449:6), who maintains that those who do this, aside for the Baal Habayis, are essentially giving up on the Mitzvah of Lechem Mishneh [on the topic of the requirement for Lechem Mishneh when doing “Pores Mapah,” see also Mishnah Berurah (271:23; citing the Magen Avraham ad loc. 11), Aruch Hashulchan (ad loc. 20), Toras Shabbos (11), Shu”t Ha’elef Lecha Shlomo (113), Shu”t Migdanos Eliyahu (146), Shemiras Shabbos Kehilchasa (vol. 2, Ch. 52, footnote 75; citing Rav Shlomo Zalman Auerbach), and Shu”t Lehoros Nosson (vol. 6:9)]; not to mention issues of ‘Tarti D’Sasri’ regarding reciting Al Hanissim or Retzei, etc. The Mishnah Berurah himself (271:21) concludes that “Raui lechol Baal Nefesh lizaher shelo yavo lidei kach.” For those who wish to perform this complicated hanhaga, this author advises to read Rav Sroyah Debilitzky’s Purim Meshulash (Ch. 1:6 and extensive footnotes) or Rav Nochum Eisenstein’s Kuntress Seudas Purim B’Erev Shabbos Kodesh to see how to accomplish this in a halachically acceptable manner.
Following the Rema’s psak (O.C. 695:2; citing the Sefer Minhagim of Rav Yitzchak Isaac Tirnau/Tyrna) of starting before Chatzos when Purim occurs on Erev Shabbos. [See also Terumas Hadeshen (110), Shlah (Megillah, Ner Mitzvah 11), Elyah Rabba (ad loc. 4), Maaseh Rav (248), and the Kabbalistic Siddur HaRashash (cited in Kaf Hachaim ad loc. 23), who maintain that every year it is preferable to have the Purim Seudah in the morning. The Pri Megadim (E.A. ad loc. 5) attests he was noheg this way as well. See also Halichos Even Yisrael (Moadim vol. 2, pg. 447:3), that Rav Yisrael Yaakov Fischer was makpid for this shittah. Rav Moshe Feinstein related (Mesores Moshe vol. 1, pg. 197:429) that his father, Rav Dovid would eat his Purim Seudah in the morning as well.] The Yosef Ometz (1104) and his descendent, the Noheg K’Tzon Yosef (Purim 14, Hagahah) were very particular about having the bulk of this Friday Purim Seudah in the morning. Rav Yosef Eliyahu Henkin, in his authoritative Ezras Torah Luach (and in the posthumously published Shu”t Gevuros Eliyahu (vol. 1-O.C. end 168) writes that on Purim Shechal B’Erev Shabbos “Seudas Purim kodem chatzos hayom.”
The Mishnah Berurah (ad loc. 10) cites the Yad Efraim (ad loc.) quoting the Maharil (Shu”t 56), that in this situation, one has a bit more time to start his Purim Seudah - until the beginning of the tenth hour (three halachic hours before shkiya; see O.C. 249:2). However, it is reported that Rav Yosef Shalom Elyashiv (Hanhagos Rabbeinu pg. 170) was makpid lechatchilla like the Rema to start his Erev Shabbos Purim Seudah before Chatzos, unless the Seudah was not ready. Similarly, Rav Shlomo Zalman Auerbach (Halichos Shlomo, Moadim vol. 1, pg. 343:26) refers to this as ‘minhag hamedakdekim’ to serve the Erev Shabbos Purim Seudah before Chatzos. The Steipler Gaon (Orchos Rabbeinu; new edition, vol. 2, pg. 185:6) did so as well, bentching before Mincha Gedolah, adding that ‘Simchas Purim continues afterwards.’
See Mishnah Berurah (249:8 and 13; Biur Halacha ad loc. s.v. muttar; and Shaar Hatziyun ad loc. 9), Aruch Hashulchan (ad loc. 7), and Shemiras Shabbos Kehilchasa (vol. 2, Ch. 42:27 and footnote 96). As an interesting counterpoint, Rav Moshe Feinstein is quoted (Moadei Yeshurun, Ch. 2, footnote 268 and Shmaatseh D’Moshe (Purim; Shemuos Moshe pg. 488:2 and footnote 27) as maintaining that it is preferable to wait to start the Purim Seudah at a later Zman if there are people expected to join him then, rather than starting earlier and having the Seudah by himself – as one cannot feel the “Simcha K’Raui” of Purim by eating by himself [see Mishnah Berurah (695:9), citing the Elyah Rabba and Shlah (ibid.); see also Mesores Moshe vol. 2, pg. 159-160:331)].
Mishnah and following Gemara in Rosh Hashana (29b), Beitzah (17b-18a), Megillah (4b), Pesachim (69a), and Sukka (42b).
See Tur and Shulchan Aruch (O.C. 688:6), based on the MishnahinMegillah (2a) and following Gemara (4b); see also Meiri and Ri M’Lunil (ad loc.) for interesting discussions whether Megillah on Shabbos shares the exact same din as Shofar and Lulav or not. There is a fascinating debate discussed by the Shaagas Aryeh in his Turei Even (Megillah 5a) regarding Purim Meshulash, that as the Megillah reading in Yerushalayim is pushed earlier to Friday (matching the rest of the world), whether it is now considered the actual proper time kavua for Krias HaMegillah, or if it is considered read earlier, before the actual zman. One ramification of this discussion is would be whether one may read the Megillah on Friday (regular Purim) without a minyan in Yerushalayim this year. Practically, the Pri Chodosh (O.C. 690:14 s.v. v’da), Mishnah Berurah (ad loc. 60 and 66, and Shaar Hatziyun ad loc. 59), and Rav Chaim Berlin (Shu”t Nishmas Chaim 77), rule that in such a case it must be leined with a minyan, otherwise a bracha may not be recited on the Kriya. The Kaf Hachaim (ad loc. 118) concurs, unless there is a specific minhag to do so. On the other hand, the Pri Megadim (O.C. 696 M.Z. 1), Ohr Somayach (Hilchos Megillah Ch. 1:7), Rav Yosef Chaim Sonnenfeld (Shu”t Salmas Chaim, original edition vol. 1:102 and 103), and Chazon Ish (O.C. 155:2; citing proof from the mashma’os of the Rambam) that in this case, Erev Shabbos is indeed considered “Zmanah,” and a minyan is not necessary. See also Minchas Asher (Moadim vol. 2, Purim 34:2). Rav Shlomo Zalman Auerbach (Halichos Shlomo, Moadim vol. 1, pg. 358:4) concludes that although practically if one cannot read the Megillah with a minyan, he may do so himself with a bracha (as is the halacha in a regular year), nevertheless, if at all possible he should strive to ensure it is leined with a minyan. Another potential implication of this discussion, especially according to the mashma’os of the Ran that the Gezeira regarding Megillah is applicable due to “Terudos” (Megillah beg. Ch. 4; see also Hagahos Baruch Taam on the Magen Avraham O.C. 692:6 who makes a similar point), would be regarding a child who became Bar Mitzvah in Yerushalayim on that Shabbos (or a case of an Oness), if he would need to and perhaps even be halachically permitted to read the Megillah on Shabbos now that he is a halachic man (and not just m’taam chinuch). Since this occurrence is extremely rare, perhaps Chazal were not gozer in such an exceptional situation. Rav Yosef Chaim Sonnenfeld is reported to be notteh to allowing this Bar Mitzvah boy to lein Megillah on Shabbos Purim Meshulash (as cited in Shu”t Tzitz Hakodesh vol. 1:55, 3), whereas the Tzitz Hakodesh himself concludes opposed. Similarly, it is reported (Shu”t Shevet Halevi vol. 5:83 s.v. v’agav) that the Brisker Rav and Rav Akiva Yosef Schlesinger had a similar debate as well, with the Shevet Halevi siding with Rav Schlesinger’s opinion that the Bar Mitzvah bachur may not lein the Megillah on that Shabbos Purim. To further complicate matters, the Pri Chodosh (ad loc. 6) ruled that the Megillah actually becomes muktzah on this Shabbos Purim. And although the Elyah Rabba (ad loc. 13), Machatzis Hashekel (ad loc. 12 s.v. v’da) and Chasam Sofer (Hagahos ad loc. 6 and Shu”t O.C. 195) argue on his logic (see Mishnah Berurah ad loc. 18), Rav Yosef Chaim Sonnenfeld wrote an extensive footnote in his Seder HaPurim HaMeshulash defending the Pri Chodosh’s position, concluding that we should certainly follow it as he was the Mara D’Asra of Yerushalayim. (This position seems leshittaso regarding the keviyus of Friday as the proper day of Kriyas HaMegillah as per his teshuvos in Shu”t Salmas Chaim; I am not entirely sure how to answer up his opinion as presented in Shu”t Tzitz Hakodesh, except that perhaps to surmise that it was only derech limud.) For more on this topic, see Cheishek Shlomo (Hagahos on Megillah 5a s.v. v’ha), Shu”t Sefer Yehoshua (Psakim U’Ksavim 226), Shu”t Har Tzvi (O.C. vol. 2:127), Mikraei Kodesh (Purim Ch. 52), Halichos Shlomo (Moadim vol. 1, Ch. 21, footnote 2), Halichos Even Yisrael (Moadim vol. 2, pg. 463), and Rav Moshe Mordechai Karp’s Dinei Purim HaMeshulash (pg. 35).
See Tur and Shulchan Aruch (O.C. 688:6), based on the MishnahinMegillah (2a) and following Gemara (4b).
Parashas Beshalach (Ch. 17:8).See Tur,Beis Yosef and Shulchan Aruch (O.C. 688:6). Although in his Beis Yosef Rav Yosef Karo writes that “matzasi kasuv” that this this is indeed Minhag Yerushlayim, and questions why Al Hanissim is not recited on Friday along with the Megillah reading, nonetheless in his Shulchan Aruch he rules that it is indeed recited on Shabbos.
Shmuel I (Ch. 15:2).
See Beis Yosef (O.C. 688:6), Darchei Moshe (ad loc. 3) and Shulchan Aruch (ad loc.) and main commentaries. For more details on the hanhagos of a Purim Meshulash, see both Rav Yosef Chaim Sonnenfeld’s Seder HaPurim HaMeshulash, Rav Chaim Pinchas HaKohen’s similarly-named Seder HaPurim HaMeshulash (under the auspices of Rav Chaim Berlin), both re-published in 1910, and Rav Sroyah Debilitzky’s Purim Meshulash.
As Gemara Megillah concludes (32a), that Moshe Rabbeinu tikein to be “Sho’elin U’Darshin B’Inyano shel Yom” – to learn each Yom Tov’s halachos on the Yom Tov itself. Hence, since Shabbos is the actual day of Purim for those observing Purim Meshulash, this requirement is on Shabbos this year. Generally speaking, this requirement is fulfilled by reading the Megillah (which, toward the end discusses the Mitzvos Hayom). But this year, as the Megillah is read on the same day of Purim as the rest of the world – it is not the actual ‘Bo Bayom’ of Shushan Purim; hence the need to mention this as a distinct inyan of its own. See Mishnah Berurah (688:16), based on Gemara Megillah (4a) and Tosafos (ad loc. s.v. Purim), as well as Lechem Mishneh (Hilchos Megillah Ch. 1:13), Dibros Moshe (Pesachim 5), and Shmaatseh D’Moshe (Hilchos Purim, pg. 392-393).
Although the proper day to perform Mishloach Manos during a Purim Meshulash is not specified by the Gemara, nonetheless the basic halacha follows the majority consensus that it is done on Sunday – the same day as the Purim Seudah. See Terumas Hadeshen (111) that a core part of the Mitzvah of Mishloach Manos is so everyone should have their ‘Tzorchei Seudah’. Hence, as the Magen Avraham (688:10) rules, Mishloach Manos is performed on the same day as the Seudah – which is Sunday. This is ruled accordingly by most later Poskim, including the Mishnah Beruruah (ad loc. 18) and Aruch Hashulchan (ad loc. 17). However, there are other varying shittos. For example, the Tikkun Yissachar (pp. 28b-29a) and Knesses Hagedolah (695, Hagahos HaTur) maintain that Mishloach Manos is akin to Matanos L’Evyonim and hence should be given on Friday, the same day as the Megillah leining. The Chazon Ish (O.C. 155:1 s.v. u’lha’amor) ruled this way as well. Other opinions include the Maharlbach (Shu”t Mahr”l ben Chaviv 32; cited by the Bach, Taz, and Magen Avraham ad loc.; see next footnote), who holds that Mishloach Manos should follow the Purim Seudah – which in his opinion, should be on Shabbos. The Yaavetz (Mor U’ketziah ad loc.s.v. v’hanireh) although agreeing with the Magen Avraham and otherPoskim that the Purim Seudah should be held on Sunday, nonetheless maintains that Mishloach Manos should be on Shabbos as it is Mitzvas Hayom, and would stand out as a Mitzvas Purim (as opposed to a Purim Seudah on Shabbos). The Pri Chodosh (ad loc. end 6) maintains that Mishloach Manos in this instance should be performed twice – on Shabbos and Sunday. The Kaf Hachaim (ad loc. 38) concludes that taking all the above into account, a Yarei Shomayim will give Mishloach Manos on all three days of Purim Meshulash (!) – but on Shabbos, only if there is an Eruv. On the other hand, the Chazon Ish (ad loc. s.v. 4b) argues that one may not fulfill Mishloach Manos on Shabbos, as not only is it “Uvda D’Chol,” but it would have the same problem of reading Megillah on Shabbos – someone potentially transgressing and carrying on Shabbos without an Eruv. Hence, in his opinion, this is not a feasible option.Yet, it is known (although he requested that it not be publicized) that Rav Shlomo Zalman Auerbach (Halichos Shlomo, Moadim vol. 1, pg. 358-359, footnote 12) some years would do give Mishloach Manos on Shabbos Purim b’tzina (privately) as a ‘Chumrah B’alma.’ Conversley, it is noted that Rav Yisrael Yaakov Fischer (Halichos Even Yisrael, Moadim vol. 2: pg. 462:13-14) in this instance would only give Mishloach Manos on Sunday of a Purim Meshulash, and not at all on Shabbos, “af lo b’tzina.”
This is the psak of the Shulchan
Aruch (O.C. 688:6), following the precedent of the Ran (Megillah 3a in the Rif’s pagination, s.v. Masnisin), explaining the Rif’s (ad loc.) citing of the Yerushalmi (Megillah Ch. 1, Halacha 4) that Seudas Purim is “Me’acharin,” pushed off - as the pasuk states (Esther Ch. 9:22) “laasos osam yemei mishteh v’simcha” – to make them days of feasting (drinking) and rejoicing; not a day that