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*Regarding hearing the reading in Shul versus arranging a Minyan in one’s house-see the next Halacha.
A. Reading the Megillah in the presence of a Minyan:
One must strive to hear the Megillah reading in the presence of a Minyan, which consists of at least ten adult men. This applies whether one celebrates on the 14th or 15th. [Thus one must strive to gather a Minyan for the local Shul reading. Likewise he may not read Megillah prior to the Shul’s reading.] This applies even if this will cause one to stop and delay learning Torah in order to join the Minyan.
Do women join the Minyan? It is questionable whether women can be counted as part of the ten people required to make a Minyan for Megillah reading. [Many Poskim conclude that women do not join the Minyan.]
If one is reading the Megillah after the local Minyan: If a certain individual needs to still hear Megillah after the local Shul’s reading, it is not necessary to gather a Minyan for this reading. [However other Poskim rule one must gather a Minyan even in such a case. Practically one is to be stringent to do so.]
One is to strive to arrange a Minyan for Megillah reading. One is certainly not to read the Megillah without a Minyan if a Minyan is available. Regarding hearing the reading in Shul versus arranging a Minyan in one’s house-see the next Halacha.
Do children join the Minyan?
Is a group of ten women considered a Minyan?
If a Minyan is already available must one strive to gather more people to join the Minyan in order to fulfill Berov Am Hadras Melech?
No. Once a Minyan is available one is not required to gather more people.
Are those that read along to themselves in a Kosher Megillah considered to fulfill the Mitzvah with a Minyan?
Yes. Some rule this applies even if he does not read word for word with the Chazan. Others rule that if he does not read word for word with the Chazan then it is not considered that he is reading with a Minyan and hence on Purim Meshulash one is to avoid reading with the Chazan even in a Kosher Megillah.
B. Reading the Megillah without a Minyan:
If one cannot find a Minyan for the Megillah reading then it is to be read without a Minyan.
The blessings: Even when reading the Megillah without a Minyan one is to recite the blessings that are said prior to the Megillah reading. However the after blessing [Harav Es Riveinu] may not be recited when reading without a Minyan. See Halacha 10 for the full details of this subject!
Reciting a blessing when the 15th falls on Shabbos: See Q&A!
Can one read on behalf of another person if a Minyan is not present? If one does not have a Minyan for the Megillah reading then if there is only one person who knows how to read the Megillah, he is to read it on behalf of the others. If however the others also know how to read the Megillah, then each person should read the Megillah to himself, as opposed to having one person read and the others listen. Some Poskim however rule that it is better for one person to read and have the others listen to his reading, even in a case that the others also know how to read the Megillah. According to all, Bedieved, if one heard the Megillah without a Minyan he has fulfilled his obligation. Practically if there is no Minyan present it is best for the person to read it himself, if he knows how to do so.
If a Minyan is not available one is to read the Megillah without a Minyan. A blessing is recited before the reading although the after blessing is omitted. One may read Megillah on behalf of others even when a Minyan is not available, although if the listeners have a Kosher Megillah and know how to read it themselves, it is better to for them to do so than to hear it from a Baal Korei when a Minyan is not present.
May those that already heard Megillah be considered part of the Minyan for the Megillah reading?
Yes. Even if nine people already heard the Megillah they can join the Minyan for a single person that did not yet hear. [Some rule that even women join the Minyan for this regard.]
On Friday of Purim Meshulash may one read the Megillah with a blessing if he does not have a Minyan?
When the 15th falls on Shabbos, and consequently the Megillah reading in Jerusalem takes place on Friday, some Poskim rule that on the Friday reading in Jerusalem the Megillah may only be read with a blessing if a Minyan is present. If however a Minyan is not present the Megillah is to be read without a blessing. Others however argue that a blessing may be recited even if a Minyan is not present. Practically the custom in Jerusalem is to read the Megillah with a blessing even if a Minyan is not available. Nevertheless initially one is to be stringent and strive to gather a Minyan for the reading, and women are to strive to join a Minyan or have the Megillah reading done with a group of ten women.
 Michaber ibid
The reason: The Rama learns that the reason for this is in order to publicize the miracle within the city, and a public matter needs to be done in front of ten people. [so is implied from Rama ibid]
Must one strive for a Minyan even after the main reading in Shul’s is complete? From the simple reading of the Michaber it implies that there is no difference in this matter and one is always obligated to strive to hear Megillah with a Minyan. However the Rama ibid rules it is not necessary and hence the above ruling only refers to a case that one desires to read Megillah before the Shul’s Minyan or if there is no Minyan in Shul. [Shaar Hatziyon 690/64] See the end of this Halacha for the full coverage of this subject.
 Michaber ibid; The novelty here is that although the 14th and 15th already contains Persumei Nissa, as a result of everyone needing to read the Megillah. Nevertheless it is required to gather a Minyan for the reading in order so there be Pirsumei Nissa during the actual reading. [M”B 690/61]
 P”M 690 A”A 23; Kaf Hachaim 690/114
 Shaar Hatziyon 690/64
 M”A 687/2 based on Michaber ibid
 Rama ibid; Dispute in Tur 689; See M”A 690/24; Machatzis Hashekel and Levushei Serud on M”A ibid that states there is no source for this doubt
 The question here is whether we hold that the Minyan for Megillah has the same laws as a Minyan for Davening, in which case women are invalid, or we hold the Minyan is needed simply to publicize the miracle and hence even women join for the Minyan. [Kaf Hachaim 690/119; M”B 690/63] Alternatively perhaps women do not join as they are not as equally obligated as are men, as women are not able to read the Megillah for others. [P”M 690 A”A 24 in explanation of M”A]
 Meiri; Orchos Chaim; Tur 689 in name of Baal Haiitur; Kol Bo 45; Peri Chadash; Shulchan Gavoa 690/45; Erech Hashulchan 690/14; Kaf Hachaim 690/120
Other Poskim: The Chazon Ish 155/2 rules that women do join the Minyan with men.
 Rama ibid
 As the Pirsumei Nissa has already been fulfilled. [Rama ibid] Now although we require one to even nullify learning Torah to join a Minyan [687/1; see next Halacha], this is only when the Minyan is available, however if there is no Minyan available [and the local Minyan already took place] then there is no requirement to gather a Minyan, and it is a mere Mitzvah Min Hamuvchar. [M”A 690/25; M”B 690/64]
 Elya Raba 690/19; Simple implication of Michaber and other Poskim; Yad Efraim; M”B 690/64; Kaf Hachaim 690/122
 M”B ibid
 P”M 690 A”A 24; M”B 690/61, however see M”B 688/20; See M”A 690/24 that mentions the Hagahos Ashri leaves this matter in question;
 As they are not obligated in the Mitzvah in it itself, other than reasons of Chinuch. [P”M ibid]
 Mahriy Algazi in Kuntrus Chug Haaretz; Salmas Chaim 1/101; Implication of Peri Chadash and P”M 690 A”A 24; Chazon Ish 155/2; Piskeiy Teshuvos 695/4, 690/12 and Melaktim mentioned there
Other Opinions: Some rule that the custom is not to recite the blessing of Harav Es Riveinu for a Minyan of women. [Halichos Bas Yisrael 22/14]
 Such as for the blessing of Harav Es Riveinu and the before blessings by Purim Meshulash, and the reading of Megillah to be Motzei others.
The reason: They hold that the above law that invalidates women is only with regards to women joining men for a Minyan, however when they have their own Minyan it suffices.
 M”A 690/23; P”M 690 A”A 23; Kaf Hachaim 690/114
 Piskeiy Teshuvos 690/10
 Chazon Ish 155/2
 Griz of Brisk
 Michaber ibid
Other Opinions: Some Rishonim [Mordechai; Bahag; Geonim brought in Orchos Chaim] rule that one is not obligated to read the Megillah if he does not have a Minyan. See Kaf Hachaim 690/124
 Rama ibid: “When an individual reads the Megillah in its proper time he needs to say a blessing over it”. So rules: Rambam; Beis Yosef in name of all Poskim; Teshuvos Maharil 56; M”B 692/8: “According to all one must say the before blessings”.
Other Opinions: Some Rishonim [Mordechai; Bahag; Geonim brought in Orchos Chaim] rule that one is not obligated to read the Megillah if he does not have a Minyan, hence in their opinion it is forbidden to say a blessing. Some Poskim conclude that one is to suspect for this opinion, especially regarding blessings, and not recite a blessing when reading the Megillah without a Minyan. [Rabbeinu Yerucham 57; See Kaf Hachaim 690/124]
 When the 15th falls on Shabbos then the reading in Jerusalem is preceded to Friday the 14th as explained in 688/6; Chapter 5 Halacha 3.
 Michaber ibid and so rules Elya Raba 689/11; Peri Chadash; Mateh Yehuda; Beis Oved 689/13; Derech Hachaim; Kaf Hachaim 689/25; M”B 689/15
The reason: According to the Michaber a person cannot help fulfill the obligation of others, in having them listen to his reading of the Megillah, unless there is a Minyan present. It is not similar to other Mitzvos, such as Shofar, in which case we do not require a Minyan, as the reading of the Megillah is similar to prayer which requires a Minyan. [M”A 689/9; M”B 689/15]
 M”A 689/9 based on Rabbeinu Yerucham Nesiv 10/3; Abudarham; Bach 690 in name of Maharil; brought in M”B 689/15
 The reason: As all the above Rishonim and Achronim [previous footnote] rule that a Yachid can read for another person without a Minyan. Hence it is even initially better to do so, as a Mitzvah is beautified when fulfilled together with others. [M”A ibid]
 Peri Chadash; Mateh Yehuda; Beis Oved 689/13; Kaf Hachaim 689/25; M”B 689/5; Implication of Elya Raba 689/11; Levush
 Mateh Yehuda; Kaf Hachaim 689/25; implication of final ruling of M”B 689/5; See Shaar Hatziyon 692/13
 Levushei Mordechai 1/137; Chazon Ish 155/2; Piskeiy Teshuvos 690/12; 692/4
 Piskeiy Teshuvos 695/4, 690/12 and Melaktim mentioned there, as they side that women do join a Minyan; ibid in name of Chazon Ish.
 Peri Chadash 690 [which was the Rav of Jerusalem] brought in Shulchan Gavoa 690/40; Mahariy Algazi in Chug Haaretz; Pnei Meivin 228; Kaf Hachaim 690/118; M”B 690/61 and 65; See Shaar Hatziyon 690/61; Implied from Rama ibid which says “proper time” hence excluding a year that Jerusalem reads on Friday the 14th. [M”B 690/65]
 The reason: As only when the Megillah is read at its proper time is a Minyan not required Bedieved. [ibid]
Which blessings may not be recited? One may not recite any of the three blessings: Neither Al Kerias Megillah; Sheasa Nissim, or Shehechiyanu. [Kaf Hachaim ibid based on Setimas Haposkim]
 Kol Eliyahu 2/28; Bnei Binyamin p. 104 brought in Kaf Hachaim ibid [The Kaf Hachaim himself is stringent]; Or Sameiach 1/15; Salmas Chaim 102-103; Chazon Ish 155/2; Ir Hakodesh Vehmaikdash 3/26-2; Yabia Omer 6/46
 As the majority of the world is reading the Megillah at this time and hence there is no greater “on its proper time” than this. [ibid]
 Poskim ibid; Piskeiy Teshuvos 690/13
Ruling of Kaf Hachaim ibid: Practically those that are lenient have upon whom to rely but every person is to be stringent.
 Piskeiy Teshuvos 690 footnote 54; Kaf Hachaim ibid