The first question is whether it is proper to read Megillat Esther in Jerusalem when it is not Purim there. In general, one should not take part in religious activity that is in conspicuous contrast to the prevalent local practice. This is based on the concept of lo titgod’du, the commandment not to break into different groups.[1]
In discussing the parameters of lo titgod’du, the gemara[2] raises the question of how it is permissible to read the Megilla on different days in different cities. The gemara[3] explains that that Jews in different cities are generally allowed to maintain different practices. There is a machloket regarding whether different rabbinical courts (i.e., separate religious communities) within one city are allowed to have different practices,[4] but different practices in different cities are certainly acceptable. Therefore, it is fine for different towns to read the Megilla at different times.
Tosafot[5] is bothered by the apparent practice of villagers who would come to the big city twice a week that they were allowed to read the Megilla in the city itself on a different day than the one on which the city dwellers would read.[6] Indeed, because of this difficulty, Tosafot claims that we must conclude that the villagers actually did not read the Megilla in the city, so as to avoid a problem of lo titgod’du; rather, they would do so before leaving their villages for the city.
Although Tosafot’s position might seem to forbid visitors from reading in Jerusalem on the 14th of Adar, we are not aware of contemporary poskim who take that approach. (In fact, common practice has generally become very lax in regard to lo tigod’du, as reflected, for example, in the prevalence of second-day-Yom Tov minyanim in Israel, but we will leave that topic aside for now.) Rather, contemporary poskim assume that one who needs to read the Megilla on the 14th can do so anywhere.[7] There are a number of explanations of why lo titgod’du does not apply in this situation. These include: 1) Lo titgod’du applies to cases of conflicting local practices that are based on conflicting opinions regarding what the correct halachic opinion is; it does not apply when different locations are supposed to have different practices, e.g., different days for Megilla reading.[8] 2) The separate reading of the villagers in the city is comparable to the case of two separate communities in one city.[9] 3) The law of two different days of Megilla reading, the 14th and the 15th of Adar, is explicit in the p’sukim and therefore will not generate negative reactions. In contrast, lo tigod’du did apply to the villagers who read earlier than the city-dwellers, because they did so without explicit sanction from the p’sukim.[10]
Rav Tzvi Pesach Frank[11] writes that one who reads the Megilla on the 14th in Jerusalem needs a minyan, just as is required of anyone who reads the Megilla not at its normal time.[12] But even people who live in Jerusalem count toward such a minyan¸ as they too help publicize the miracle. However, most poskim do not require a minyan in this case.[13]
Another relevant question is whether a Jerusalemite can be the ba’al korei on the 14th in Jerusalem. The Yerushalmi[14] raises this question with the following explanation of the dilemma: Although one who fulfills a mitzva on behalf of another must be obligated in the mitzva, perhaps the fact that a Jerusalemite who reads the Megilla on the 14th fulfills the mitzva b’di’eved is enough to make him be considered “obligated in the mitzva.” The Pri Chadash[15] understands that the Talmud Bavli[16] disagrees with the Yerushalmi’s assumption and posits that a Jerusalemite cannot fulfill Megilla reading on the 14th even b’di’eved. However, the Pri Megadim[17] and the Gra[18] maintain that the Bavli agrees that while a Jerusalemite should read only on the 15th, his reading on the 14th counts, and Rav O. Yosef agrees with this opinion. Thus, it is quite possible that a Jerusalemite could read the Megilla for the visitors on the 14th.[19]
We suggest that if there is no one who is obligated in a 14th-of-Adar reading who can serve as the ba’al korei, your guests should try to find late readings in their community. However, if this is not feasible, they can rely on the reading of a Jerusalemite. In that case, one of the visitors, not the ba’al korei, should make the beracha on the reading.[20]