Talmud - Ta'anit 18b תענית י״ח ב׳

as the Sages decreed that in certain places one may read the Scroll of Esther on the eleventh, twelfth, or thirteenth of Adar, nevertheless, it is permitted to eulogize and fast on these days. The Gemara clarifies: When does this ruling apply? If we say that it applies to those in walled cities, who normally read the scroll on the fifteenth of Adar and yet this year they read it on the fourteenth, a day on which they normally are permitted to fast and eulogize, but this cannot be the case, as are they permitted to fast and eulogize at all on these days?

But isn’t it written in Megillat Ta’anit: The day of the fourteenth of Adar and the day of the fifteenth of Adar are the days of Purim, on which eulogizing is prohibited. And Rava said: Since these days are already mentioned in the Bible (Esther 9:18–19), it is necessary to state this halakha in Megillat Ta’anit only to prohibit those living in these walled cities from fasting and eulogizing on this date, the fourteenth, and those living in these non-walled cities from fasting and eulogizing on this date, the fifteenth.

The Gemara continues its explanation of the difficulty. But rather, the mishna must be referring to those who normally read on the fourteenth of Adar, but who read the Scroll of Esther early, on the thirteenth. However, it is already prohibited to fast on the thirteenth, as it is Nicanor’s Day, which is a commemorative day in its own right. But rather, you will say that the mishna is referring to those residents of cities who normally read on the fourteenth, but who read it early that year, on the twelfth; however, the twelfth of Adar is also a commemorative day, as it is Trajan’s Day.

Rather, isn’t the mishna referring to a case where they read the Scroll of Esther on the eleventh of Adar, and nevertheless that mishna teaches that it is permitted to eulogize and fast on this day, despite the fact that it is the day before Trajan’s Day? The opinion in this unattributed mishna is not in accordance with that of Rabbi Yosei, which means that there is a contradiction between the two statements of Rabbi Yoḥanan.

The Gemara answers: No; the mishna is actually referring to those who normally read on the fourteenth, but who read it that year on the twelfth of Adar. And with regard to that which you said, that it is Trajan’s Day, Trajan’s Day itself was annulled and is no longer celebrated, since Shemaya and his brother Aḥiya were killed on that day. We learn this as in the incident when Rav Naḥman decreed a fast on the twelfth of Adar and the Sages said to him: It is Trajan’s Day. He said to them: Trajan’s Day itself was annulled, since Shemaya and his brother Aḥiya were killed on that day.

The Gemara asks: And let him derive that fasting on the twelfth is prohibited in any case, as it is the day before Nicanor’s Day. Rav Ashi said: Now that with regard to Trajan’s Day itself, they annulled it, will we then arise and issue a decree not to fast on this date due to the following day, Nicanor’s Day?

In relation to the above, the Gemara inquires: What is the origin of Nicanor’s Day and what is the origin of Trajan’s Day? As it is taught in a baraita: Nicanor was one of the generals [iparkhei] in the Greek army, and each and every day he would wave his hand over Judea and Jerusalem and say: When will this city fall into my hands, and I shall trample it? And when the Hasmonean monarchy overcame the Greeks and emerged victorious over them, they killed Nicanor in battle, cut off his thumbs and big toes, and hung them on the gates of Jerusalem, saying: The mouth that spoke with pride, and the hands that waved over Jerusalem, may vengeance be taken against them. This occurred on the thirteenth of Adar.

What is the origin of Trajan’s Day? They said in explanation: When Trajan sought to kill the important leaders Luleyanus and his brother Pappas in Laodicea, he said to them: If you are from the nation of Hananiah, Mishael, and Azariah, let your God come and save you from my hand, just as He saved Hananiah, Mishael, and Azariah from the hand of Nebuchadnezzar. Luleyanus and Pappas said to him: Hananiah, Mishael, and Azariah were full-fledged righteous people, and they were worthy that a miracle should be performed for them, and Nebuchadnezzar was a legitimate king who rose to power through his merit, and it is fitting that a miracle be performed through him.

But this wicked man, Trajan, is a commoner, not a real king, and it is not fitting that a miracle be performed through him. Luleyanus and Pappas continued: And we are not wholly righteous, and have been condemned to destruction by the Omnipresent for our sins. And if you do not kill us, the Omnipresent has many other executioners. And if men do not kill us, the Omnipresent has many bears and lions in His world that can hurt us and kill us. Instead, the Holy One, Blessed be He, placed us into your hands only so that He will avenge our blood in the future.

Even so, Trajan remained unmoved by their response and killed them immediately. It is said that they had not moved from the place of execution when two officials [diyoflei] arrived from Rome with permission to remove Trajan from power, and they split his skull with clubs. This was viewed as an act of divine retribution and was established as a commemorative day.

§ The mishna taught: One may not decree a fast on the community starting on a Thursday, so as not to cause prices to rise. Furthermore, one may not decree a fast on New Moons, on Hanukkah, or on Purim. However, if one began a set of fasts, one does not interrupt the sequence for these days. The Gemara asks: And how many fasts are considered a beginning? Rav Aḥa said: If one fasted three fasts before the festive day. Rabbi Asi said: Even if one fasted one fast before it.

Rav Yehuda said that Rav said: This halakha of the mishna that a fast that occurs on a festival is not observed, is the statement of Rabbi Meir, who said it in the name of Rabban Gamliel. However, the Rabbis say: If a communal fast occurs on one of these days, one must fast and complete the fast until nightfall. Mar Zutra taught in the name of Rav Huna: The practical halakha is in accordance with the opinion of the Rabbis, that one fasts and completes his fast until nightfall.

MISHNA: The order of these fasts of increasing severity, as explained in Chapter One, is stated only in a case when the first rainfall has not materialized. However, if there is vegetation that grew and its appearance changed due to disease, the court does not wait at all; they cry out about it immediately. And likewise, if rain ceased for a period of forty days between one rainfall and another, they cry out about it because it is a plague of drought.

If sufficient rain fell for the vegetation but not enough fell for the trees; or if it was enough for the trees but not for the vegetation; or if sufficient rain fell for both this and that, i.e., vegetation and trees, but not enough to fill the cisterns, ditches, and caves with water to last the summer, they cry out about it immediately. And likewise, if there is a particular city upon which it did not rain, while the surrounding area did receive rain, this is considered a divine curse, as it is written: “And I caused it to rain upon one city, but caused it not to rain upon another city; one piece was rained upon, and the portion upon which it did not rain withered” (Amos 4:7).

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Taanit 18b examines when Purim readings on varied Adar dates allow fasting or eulogizing, weighing this against Nicanor's Day and Trajan's Day restrictions.