(Mishnah): In a place where the custom is to do Melachah on Erev Pesach until noon, one may do so. In a place where the custom is to refrain, one may not do Melachah.

One who goes from a place where they do Melachah to a place where they do not, or from a place where they do not do Melachah to a place where they do, we give him the stringencies of the place from which he left and the place to which he came. A person should not act differently (to the location that he is), in order to avoid dispute.

(Gemara): The Pasuk states (Devarim 16,6), "There you shall sacrifice the Pesach in the afternoon''. I would only know about him; from where do I know to include his messenger? The next Pasuk states, "and you shall roast it and you shall eat it'' - this implies that the Pasuk is only concerned about he himself roasting and eating it, but it could be sacrificed through a messenger. What do we learn from "there you shall sacrifice the Pesach in the afternoon''? It is not correct that you should be involved in your Melachah whilst your sacrifice is being brought - rather, the Pasuk prohibited doing Melachah at this time.

It is comparable to that which is taught in Megilas Taanis, "Therefore, anyone who is obliged to bring wood and Bikurim''.

Explanation: One who says, "I am obligating myself to bring wood for the altar and wood strips for the woodpile'', he is prohibited that day to eulogize, to fast and to do Melachah.

(Rav Yona): These [daily] Tamid offerings are the sacrifices of all of Israel. If you say that all of Israel should go to Yerushalayim, the Pasuk states merely that (Devarim 16,16), "three times a year all of your males will be seen''. If all of Israel would sit idly (refraining from Melachah as Megilas Taanis requires), the Pasuk states (Devarim 11, 14), "...and you shall gather your grains'' - who will gather the grain? Rather, the Neviim established 24 Mishmaros (watches of Kohanim), with a representation of Kohanim, Leviim and Yisraelim for each Mishmar standing in Yerushalayim.

(Beraisa): 24,000 people would be an Amud from Yerushalayim and half an Amud would come from Yericho. Even Yericho was able to supply a full Amud but out of respect for Yerushalayim, it would only supply half an Amud. The Kohanim would perform the divine service, the Leviim would be on the platform (singing as part of the divine service) and the Yisraelim would stand and represent all of Israel.

(Beraisa - Raban Shimon ben Elazar): The following were all key elements of the divine service - Kohanim, Leviim, Yisraelim and song.

Explanation (R. Abun quoting R. Elazar): R. Shimon ben Elazar's source is the Pasuk (in Divrei Hayamim 2,29,28), "All of the assembly were bowing down'' - this is the Yisraelim; "and the song was being sung'' - this is the Leviim; "and the trumpets were sounding'' - this is the Kohanim; "all of this until the Olah offering was finished [burning]'' - all of these people were crucial for the sacrifice.

An alternative source (R. Tanchuma quoting R. Elazar): The Pasuk states (Bamidbar 8, 19), "And then I appointed the Leviim to be presented to Aharon and his sons from amongst Bnei Yisrael'' - these are the Leviim; "to serve the service of Bnei Yisrael in the Tent of Meeting'' - these are the Kohanim; "to atone for Bnei Yisrael'' - this is the song; "and there will not be a plague amongst Bnei Yisrael when Bnei Yisrael approach the holy place'' - these are the Yisraelim.

Question: What is the source that song is called atonement?

Answer (Chinana quoting R. Benaya): (ibid) "And to atone on Bnei Yisrael'' - this is the song.

Question: What is the source that the song is crucial to the sacrifice?

Answer (R. Yaakov/ R. Shimon quoting R. Chanina): (ibid) "And to atone on Bnei Yisrael'' - this is the song.

Question: The Korban Pesach is a sacrifice of all of Yisrael and nevertheless, customs differ as to performing Melachah on the day of Erev Pesach (so how could it be said that the Torah prohibits Melachah on the day a sacrifice is brought (see earlier (e)))?

Answer (R. Abahu): Since the Korban Pesach is only brought after the 6th hour.

Query (R. Abahu): One who says, "I am obligating myself to bring an Olah offering after the 6th hour'', is he prohibited to do Melachah before the 6th hour? (See Korban Ha'Edah)

(R. Yosa): (It is prohibited to do Melachah before noon) - A Korban Pesach that was sacrificed in the morning [of the 14th] is not considered a Korban Pesach; but an Olah offering sacrificed in the morning is considered an Olah (therefore Melachah is prohibited).

Many things depend on customs -

Women who are accustomed not to do Melachah on Motzai Shabbos - it is not a valid custom.

To refrain from Melachah until after the Kedushah prayers in the Shul on Motzai Shabbos - it is a valid custom.

To refrain from Melachah on Monday and Thursday - it is not a valid custom.

To refrain until after the public fast - it is a valid custom.

To refrain from Melachah on Erev Shabbos and Erev Yom Tov - it is not a valid custom.

But to refrain on these days after the time of Minchah - it is a valid custom.

To refrain from Melachah on Rosh Chodesh (the New Moon) - it is a valid custom.

(R. Zeira): Women who are accustomed to refrain from arranging the threads along the length (Shesi) of a garment after Rosh Chodesh Av - it is a valid custom; as it was at this time that the Even Shesiya was eliminated from the Holy of Holies when the Beis Hamikdash was destroyed - as the Pasuk states (Tehillim 11,3), "When the foundations (Shesus) will be destroyed''.

(R. Chinana): Many things are customs....

There were these Cedar trees in Migdal Tzvaya (from which Yaakov Avinu took wood to Egypt to be used in the future for the Mishkan - they had originally been planted by Avraham Avinu for this purpose). The people came to ask R. Chanina if they were allowed to use the trees for their own benefit (as they had already been used for their intended mitzvah). He answered that since their forefathers had been accustomed not to use them, they should not change their forefathers' custom.

(R. Elazar quoting R. Avun): Anything that one is not aware is permitted and he mistakenly treats it as prohibited, if he asks, they will permit it to him (as it is a mistaken custom). But anything that one knows is permitted and he treats it as prohibited, if he asks, they will not permit it to him.

One may sit on the bench of an idolater on Shabbos (who uses it when making sales). (Strictly speaking it is permitted but the custom became to prohibit it to avoid suspicion.) There was a story about Rabban Gamliel who sat on such a bench on Shabbos in Acco. They said to him that they were not accustomed to sit on the bench of an idolater on Shabbos. He did not want to tell them that it was only a custom but strictly speaking it was permitted; rather, he arose and left.

There was a story with Yehudah and Hillel the sons of Rabban Gamliel who bathed in the bathhouse of Kabul. The people told them that our custom is that two brothers do not wash together. The brothers did not wish to tell them that it was permitted; rather, they entered one after another.

They later went out on Shabbos evening to walk in Biro wearing Kordakiyos (wide sandals) of gold. The people told them that our custom is to refrain from walking on Shabbos in Kordakiyos of gold (as there was a concern that the sandal might slip off and they would carry it on Shabbos). The brothers did not wish to tell them that it was permitted; rather they sent the shoes home with their servants.