[San 12b.1: We begin 8 lines from the top of the page.]
A master said [citing the b'raita from the previous page]: R' Yehudah says that we intercalate [add a month before Pesach] because of impurity. It appears that R. Yehudah holds that impurity in the community is postponed. [Normally,sacrifices cannot be brought by Kohanim who are in a state of impurity and the Paschal lamb cannot be brought by people in a state of impurity. But, by biblical law, impurity does not stop sacrificial rites if the majority of Kohanim [in the case of time-dependent communal sacrifices] or the majority of the people [in the case of the Paschal sacrifice] are impure. The question is whether the impurity is postponed [so that other aspects of the impurity remain in effect] or is permitted [in which case the impurity completely disappears]. If the impurity were fully permitted, there would be no reason to intercalate an extra month before Pesach, even if most people were impure. But R. Yehudah rules that one does intercalate because of impurity, which implies that the impurity is postponed, but should still be avoided if possible, even by intercalation.]
[The next b'raita deals with the tzitz, the golden headpiece worn by the High Priest. If a sacrifice becomes impure,the tzitz can override the impurity and make the sacrifice acceptable.]
But we learned in a b'raita: The tzitz, whether or not it was on the forehead (of the High Priest when the sacrifice became impure) it is acceptable; these are the words of R. Shimon.R. Yehudah says: If it was on his head (at the time the sacrifice became impure), it (the sacrifice) is acceptable; if not, it is not. R. Shimon said: The High Priest on Yom Kippur proves (my case), for even when it is not on his head (when he enters the Holy of Holies) it still makes the sacrifice acceptable. R. Yehudah said: Disregard the case of Yom Kippur, because impurity is permitted for communal needs [and the tzitz is not needed in order to make the sacrifice acceptable]. [Note that R. Yehudah rules that impurity is permitted, not simply suspended, and is thus inconsistent with the opinion ascribed to him in the previously cited b'raita.]
But according to you (who pointed out the contradiction), that b'raita is itself problematic. R. Yehudah said that we intercalate [because of impurity], and R. Yehudah described the incident with Hezekiah, King of Judea, who intercalated the year because of impurity, and he sought Divine Mercy! [If R. Yehudah holds that intercalation for impurity is acceptable, why did Hezekiah have to seek Divine Mercy?]
Instead, there are words missing from the b'raita, and this is how we should learn it: We do not intercalate the year becauseof impurity, but if we did so, it is intercalated. R. Yehudah says that it (intercalation) is not effective (even after the fact), and R. Yehudah described, etc.. [the incident with Hezekiah, whose asking for Divine mercy proves that the intercalation was erroneous].
If so [if the the dispute between R. Shimon and R. Yehudah was over whether intercalation is effective after the fact], then [what of the b'raita's text that] R. Shimon says that if we intercalated, it is effective -- that is the same position as the Tanna Kamma [the anonymous author of the b'raita]? [If both the Tanna Kamma and R. Shimon hold that intercalation after the fact is binding, why mention both opinions?]
Rava said: The difference [between the Tanna Kama and R.Shimon is not whether post facto intercalation is effective [both agree that it is] is whether we intercalate (because of impurity) in the first place.
This was indeed taught in a b'raita: We do not intercalate the year because of impurity in the first place. R. Shimon says that we do intercalate. So why did he [King Hezekiah] seek Divine Mercy? Because we only intercalate Adar [the month before Pesach], and heintercalated Nisan in the month of Nisan.
[San 12b.2; We begin on the fourth line above the wide lines. A master said [in a b'raita]: We intercalate [a leap year] only in Adar, and he [Hezekiah] intercalated Nissan in the month of Nissan [which is why he sought Divine Mercy]. But didn't Hezekiah accept: "This month shall be unto younthe beginning of months" (Ex 12:2), to mean this Nissan and no other Nissan [Rashi: that one cannot wait until Nissan and then declare it to be the intercalated month of the second Adar]?
Hezekiah made a mistake in understanding Shmuel's ruling. Shmuel said that we do not intercalate on the thirtieth day of Adar, given that it could have been designated the first day of Nissan. But he [Hezekiah] held that "because it could have been designated" was not binding [i.e., did not foreclose on the opportunity to intercalate]. [In line with the Talmudic principle that halakhah is timeless, it is assumed that the ruling made by Shmuel in Babylonia in the 3rd century C.E. should have been known to King Hezekiah in the 7th Century B.C.E.]. And this was also taught in a b'raita: We do not intercalate on the thirtieth day of Adar, because it could have been designated as the first day of Nissan.
R Shimon b. Yehudah said in the name of R. Shimon: (Hezekiah sought mercy) because he misled the people regarding Pesach Sheni [the Second Passover, biblically ordained for those who were impure or traveling on the Passover]. How so? Rav Ashi said that half the people were impure and half were pure, but the women made the majority pure. [Rashi: Fewer than half the men were pure, but more than half the women were pure. Thus, if one counted only the men, then most of the community was impure, and the Paschal sacrifice could be brought despite the impurity. If one counted the women too, most of the people were pure, and the impure people would have to wait until Pesach Sheni. There was a dispute -- see below -- as to whether the women should have been counted.]
Originally he [Hezekiah] thought that women were obligated to bring the Paschal sacrifice, and only a minority [of the entire eligible population] was impure, and they were deferred until Pesach Sheni. [Therefore, he postponed the celebration.] Eventually he held that women's obligation for the Paschal sacrifice was voluntary, so the majority of obligated individuals [the men only] were impure, and an (impure) majority does not defer Pesach Sheni. [Therefore, he realized that he had sinned and asked for Divine mercy.]
[We now return to Shmuel's ruling.] Shmuel said: We do not intercalate on the thirtieth day of Adar, because it could be designated as the first day of Nissan. And what if they did intercalate? Ulla said: They should not sanctify it as Adar Sheni [Rashi: They should not call it Adar Sheni, but when the next New Month is declared, it will be Nissan]. And what if they did sanctify it (as Adar Sheni)? Rava [perhaps Rabba] said: It is invalid; Rav Nachman said: It (the year) is extended, and it (the month) is sanctified [i.e., it is indeed Adar Sheni].
Rava said to Rav Nachman: Let us see. From Purim to Pesach is thirty days, and, starting with Purim, we teach about the laws of Pesach, as it says in a b'raita: We study the laws of Pesach thirty days before Pesach. Rabban Shimon b. Gamliel said: Two weeks. But when the New Month begins [two weeks after Purim], and we postpone it [we declare the month after Purim to be Adar Sheni], people will become careless about hametz [on Pesach, assuming that the month after Purim is Adar Sheni, not Nissan]. He [Rav Nachman] said: People understand that intercalation depends on calculation, and [if Adar Sheni is declared after Purim] that the rabbis didn't complete their calculations. [In effect, Rav Nachman assumes that people will not make the error.]
[We end two lines from the bottom of San 12b.]