The Megilah is never read before the 11th or after the 15th of Adar.

Walled cities read on the 15th

(Open) cities read on the 14th

(People in) villages read on the day of assembly (the last Monday or Thursday before or on the 14th).

When the 14th falls on Friday, both open and walled cities read that day. When it falls on Shabbos both open cities and villages read on Thursday.

Question: What is the source that villages (must) read early?

Objection: They need not read early - we shall learn that Chachamim were lenient to allow villages to read early, so they will be free to supply food and water to the cities on Purim!

Clarification of Question: If Anshei Keneses ha'Gedolah decreed that all must read on the 14th or 15th, how could later Chachamim uproot this?

(Mishnah): A Beis Din can overturn the decree of a previous Beis Din only if it is greater in Chachmah and number (of Talmidim)!

Answer: Anshei Keneses ha'Gedolah themselves enacted all these days.

Question: What is the source of this? (The Megilah mentions only the 14th and 15th.)

Answer #1 (R. Shemen bar Aba): We learn from "Lekayem Es Yemei ha'Purim ha'Eleh bi'Zmaneihem" - many times were enacted.

Question: This is needed to teach about the 14th and 15th!

Answer: It could have said Zeman - rather, it says Zemaneihem to teach that there are additional times.

Question: We need this to learn than one who should read on the 14th may not read on the 15th, or vice-versa!

Answer: Had it said Zemanam, we would have learned only one extra law; "bi'Zmaneihem" teaches two additional laws.

Question: We should say that even more days are allowed!

Answer: The extra days are like the primary days, i.e. there are two.

Question: We should say that 12 and 13 are the extra days!

Answer (Rav Shmuel bar Yitzchak): Surely we do not need a source to allow the 13th. It was the day of assembly! (Rashi - Yisrael took vengeance from their enemies; R. Tam - they gathered to fast and pray.)

Suggestion: Perhaps we include the 16th and 17th!

Rejection: "V'Lo Ya'avor" (do not pass over the times for reading).

Answer #2 (R. Shmuel bar Nachmani): "Ka'Yomim Asher Nachu Vahem" teaches about the 11th and 12th.

Questions and Answers (m) through (p) are repeated verbatim.

Question: Why didn't R. Shmuel learn from "bi'Zmaneihem"?

Answer: R. Shemen holds that since it says "bi'Zmaneihem", as opposed to Zemanam or Zeman, this warrants learning two extra laws - R. Shmuel disagrees.

Question: Why didn't R. Shemen learn from "Ka'Yomim..."?

Answer: He says that those words teach that the Mitzvah applies on these days in all generations.

Version #1 (Rabah bar bar Chanah): Our Stam Mishnah is like R. Akiva, but Chachamim say that we may read only on the 14th and 15th.

Question (Beraisa #1- R. Yehudah): The extra days are allowed only when the years and months are decided properly (by the Sanhedrin, and messengers inform people which day was made Rosh Chodesh) and Benei Yisrael are in Eretz Yisrael.

Whose opinion does R. Yehudah follow? It cannot be R. Akiva since he does not qualify when the extra days are allowed (and he allows them even nowadays).

If so, R. Yehudah must hold like Chachamim - and he permits extra days! (We may not say that he is a third opinion, for we cannot posit a three-way argument among Tana'im unless this is inescapable.)

Version #2 (Rabah bar bar Chanah): Our Mishnah is like R. Akiva, but Chachamim say that nowadays, when people look to the day of the reading (to know when Pesach will be), we only read in the primary time. (Pesach is 29 or 30 days after Purim in walled and open cities, respectively.)

Support (Beraisa #1 - R. Yehudah): The extra days are allowed only when the years are proper and Benei Yisrael are in Eretz Yisrael, not nowadays when people look to the day of the reading. (end of Version #2)

Rav Ashi established Beraisa #1 to be like R. Yosi b'Rebbi Yehudah to avoid a contradiction:

Contradiction (Rav Ashi): Elsewhere, R. Yehudah allows villages to read early even nowadays!

(Beraisa #2 - R. Yehudah): Villagers may read early only in places where they enter the cities on Mondays and Thursdays.

This applies even nowadays!

Resolution (Rav Ashi): The Tana of Beraisa #1 is R. Yosi b'Rebbi Yehudah.

Question: A difficulty does not justify saying that a different Tana taught the Beraisa!

Answer: Rav Ashi had heard that some attribute Beraisa #1 to R. Yosi b'Rebbi Yehudah.

Question: What is the source of this law?

Answer (Rava): The verse says that open cities celebrate the 14th; we infer that walled cities celebrate the 15th.

Question: Perhaps walled cities do not celebrate at all!

Answer #1: Surely, all Yisraelim should celebrate!

Answer #2: Achashverosh's kingdom was from Hodu until Kush (i.e. the entire world, and all the Yisraelim in it accepted the enactment of Purim).

Question: Perhaps walled cities must celebrate both - it says "to make the day of the 14th... v'Es (and) the day of the 15th... "!

Answer: "V'Es" separates them; these (open cities) celebrate the 14th, and these (walled cities) celebrate the 15th.

Question: Perhaps walled cities may celebrate either day!

Answer: "Bi'Zmaneihem" - each has its own separate time.

Question: Perhaps walled cities celebrate the 13th!

Answer: We learn from Shushan (they made the 15th a Yom Tov - Esther 9:18).

Question: The verses teach on which day to make a Mishteh and Yom Tov - what is the source that this is the proper day to read the Megilah?

Answer: "The days are remembered and made" - we equate remembering (reading) with making a festive meal and Yom Tov.

Our Mishnah is unlike the following Tana:

(Beraisa - R. Yehoshua ben Korchah): Cities surrounded by a wall from the time of Achashverosh read on the 15th.

Question: What is his reason?

Answer: We learn from Shushan, which was surrounded by a wall from the time of Achashverosh.

Question: What is the reason of the Tana of our Mishnah?

Answer: He learns from a Gezeirah Shavah "Prazi-Prazi" from the cities of Sichon and Og, which were surrounded from the time of Yehoshua.

R. Yehoshua ben Korchah did not learn like our Tana because he had no tradition for the Gezeirah Shavah.

Question: Why didn't our Tana learn like R. Yehoshua ben Korchah?

Objection: We said that he learns from a Gezeirah Shavah!

Clarification of question: According to our Tana, Shushan should celebrate the 14th (we have no source that it was surrounded from the time of Yehoshua)!

Answer (Rava, or anonymous): Shushan is special, since the miracle was there. (They were given another day to kill their enemies, and rested on the 15th.)

Question: According to our Tana, we understand "Medinah u'Mdinah" - this distinguishes between walled cities from the time of Yehoshua bin Nun and those surrounded by a wall afterwards; "v'Ir va'Ir" distinguishes between Shushan and all other cities not surrounded by a wall from that time;

R. Yehoshua ben Korchah can similarly use "Medinah u'Mdinah" to distinguish between cities surrounded from the time of Achashverosh and those surrounded afterwards;

But what can he learn from "v'Ir va'Ir"?

Counter-question: Likewise, our Tana should not need to learn from "Medinah u'Mdinah", since he has a Gezeirah Shavah!

Answer to both questions: Both Tana'im must expound the extra words to teach the following:

(R. Yehoshua ben Levi): Any place close to a walled city or that can see a walled city has the law of a walled city.

Question: What is considered close?

Answer (R. Yirmeyah): It is as far as from Chamsan to Teverya, one Mil.

Question: Why didn't he simply say one Mil?

Answer: He wanted to teach the size of a Mil.