Why is the megillah read in Jerusalem on the l5th day of Adar, in New York on the 14th day of Adar and in Safed and Hebron on the 14th and the 15th of Adar? On what day does an American tourist read the megillah in Jerusalem and when does an Israeli tourist read the megillah in New York? Why is the megillah read twice during the same day, once at night and once during the day? If one can only attend one reading of the megillah, which should one choose? Why does Purim outside of Israel never occur on Shabbat? When Purim in Israel occurs on Shabbat, why is the megillah read on Friday? Can the megillah be recited in English? Can the mitzvah of listening to the megillah be fulfilled over the telephone or the radio? Can a loudspeaker be used?
Those who reside in a city, such as Jerusalem, which was surrounded by a wall in the days of Joshua, recite the megillah on the 15th day of Adar. Those who reside in cities – such as Safed and Hebron – about which there is uncertainty as to whether they were surrounded by a wall in the days of Joshua, are required to read the megillah both on the 14th and the 15th days of Adar. Residents of all other cities recite the megillah on the l4th day of Adar. The reason for this distinction is that in Shushan itself the battle continued on through the 14th day and Purim was celebrated on the 15th. Because Shushan was a walled city in Mordechai’s day, all other walled cities celebrate Purim on the 15th day of Adar. But out of deference to the cities of Israel, most of which had been destroyed before Mordechai’s time, the relevant time chosen by the Sages to determine whether a city was surrounded by a wall was the time of Joshua.
A tourist in Jerusalem who originally planned to leave Jerusalem prior to the 15th day of Adar recites the megillah in Jerusalem on the 14th day of Adar even if, contrary to his original plans, he still finds himself in Jerusalem on the 15th of Adar. If, however, such a person originally intended to be in Jerusalem on the 15th of Adar, he recites the megillah in Jerusalem on the 15th. Conversely, a resident of Jerusalem visiting New York who originally planned to return to Jerusalem prior to the 14th day of Adar recites the megillah in New York on the 15th day of Adar, even if, contrary to his plans, he still finds himself in New York on the 14th day of Adar. If, however, such a person originally intended to be in New York on the 14th of Adar, he recites the megillah in New York on the 14th of Adar.
Reciting the megillah on the day of the fifteenth has greater significance than reciting the megillah at night on the eve of the fifteenth. This is because the daytime reading was instituted by Mordechai and Esther whereas the nighttime reading was subsequently instituted by the rabbis. Accordingly, if circumstances force one to choose one reading over the other, most authorities agree that one should attend the daytime reading. Others argue that rule of ein ma’avirim al hamitzvot, (do not offend a mitzvah by postponing it) requires that one choose the nighttime reading.
Because Yom Kippur can never occur on a Friday, the 14th day of Adar can never occur on a Shabbat. If the 15th day of Adar occurs on a Shabbat, the megillah is read in Jerusalem on a Friday. This is out of the dual concern that people would carry the megillah in the streets and would not be able to give money to the poor on Shabbat.
One can fulfill the mitzvah of listening to the megillah as long as one hears the voice of the person reciting the megillah on one’s behalf. Most poskim agree, therefore, that listening to a live broadcast of the megillah over the radio or the telephone is unacceptable because you are listening to an electronic transmission of the reader’s voice rather the voice itself. According to Rabbi Ovadia Yosef, a microphone is unacceptable. This is because, according to his understanding, the membrane of the microphone absorbs the human voice and then emits an electronic version of it.
According to Rabbi Moshe Feinstein, however, a microphone is halachically acceptable because the transmission is simultaneously activated by the human voice. Rav Yosef concedes that a microphone may be used to amplify the reader’s voice in a case where the reader’s voice would still be audible without it.