009a – אין נערכין – פרק שני – ערכין, דף ט ע”א

[If so,] the new moon would appear three days early!^[1]

קדים [אתי] סיהרא - The new [moon appears] three days before Rosh Hashanah, for example, when the molad was on Wednesday and Rosh Hashanah on Shabbos; and people murmur against the Rabbis, saying: they do whatever they wish.^[2]

Now too, it appears two days early!^[3]

As Rav Mesharshiya said: for example, where the year was intercalated; here too, for example, where the preceding year was intercalated, and the intercalation of a year is “a month”: set the full month off against the deficient month.^[4]

כדאמר רב משרשיא - Below, regarding Atzeres: for example, where the year was intercalated; here too, for example, where the preceding year was intercalated.

עיבור שנה חדש - It is in our hands to make the added month of the year either full or deficient. Last year’s intercalated month we made deficient, so it emerges that we set last Tishrei ahead of its molad by the measure of one month’s deficiency; therefore we may delay this Tishrei by the measure of one month’s fullness, as he says: set the full month off against the deficient.

But there is still one day!

ואכתי חד יומא - Although it is a day and a half, he calls it one day. Likewise, had this year itself been intercalated, he could also have answered that it is proper to make eight months full. The reason he took “the preceding year” is that our Mishnah cannot be set in an intercalated year, since it teaches: one does not make fewer than four full months, implying that four full months suffice, and in an intercalated year nine deficient months would remain; and both according to Rav Huna and according to Ulla^[5] even eight deficient can be set only in an intercalated year, but nine, neither in an ordinary year nor in an intercalated one, as below.

People do not take notice of [one day].

לא אדעתייהו דאינשי - Over one day they are not astonished and do not murmur.

Ulla said: It did not seem proper to the Sages to make more than eight months deficient.

And he is stating the reason: what is the reason that one does not make fewer than four full months in a year?^[6] Because it did not seem proper to the Sages to make more than eight deficient.

What is different about nine, that one does not [make them deficient]?

For if so, the [old] moon would linger three days.^[7]

מייתרא סיהרא - The old [moon lingers] three days after Rosh Hashanah, for the order of the months, following the molad of the moon, is one full and one deficient, as I explained; and when you make three more deficient, you bring Rosh Hashanah three days earlier.

Now too, it lingers two days!^[8]

As Rav Mesharshiya said: for example, where the year was intercalated; here too, for example, where the preceding year was intercalated: set the deficient month off against the full month.^[9]

שהיתה שנה שלפניה - Last year was intercalated, and the intercalated month was thirty days, while by the moon’s count it is only twenty-nine and a half; it emerges that Rosh Hashanah was delayed by half a day, and now [the moon] precedes Rosh Hashanah by only a day and a half. Since that is not two whole days, he counts it as one. And this is what he asks: But there is still one day!

But there is still one day!

They think: it was seen [by the court], and we did not pay attention.^[10]

איתחזויי איתחזי - The moon was seen by the court, and it is we who did not trouble ourselves to look for it; therefore they do not murmur.

Tosfos

הכא נמי כגון שהיתה שנה שלפניה מעוברת - We are dealing with that same year, and he should have said that this year is intercalated, and that is why we make eight full months, as in here too, for example, where the preceding year was intercalated, meaning: this year, in which we made eight full months. Were it not for the intercalation, if last year the fixing and the molad were on Shabbos, this year the fixing, with the months in their order, would be on Wednesday (on which the molad falls), and when full months are added it is delayed yet another day, to the seventh day. [But with the intercalation] the molad fell on Thursday at 21 hours and was not seen until Friday;^[11] so it precedes by only one day.

מחד יומא לא אדעתא דאינשי - This implies that nowadays they make eight full months where [the moon] precedes by only one day. This is difficult: nowadays we postpone for GaTRaD^[12] because in the coming year [the molad] would be on the seventh day at 18 hours, and [Rosh Hashanah] would be fixed on Monday, and there would be six [days, a year of 356], and we would make two [extra] full months, and still there would be only one day! One must say that those who arranged the intercalations and fixings for us did not wish to institute that the year should ever be lengthened by more than seven full months.

מאי טעמא שלש חסירים דלא - For if so, the [old] moon would linger three days: in their order, the fixing would fall on the day of the molad, on Wednesday, and because of three deficient months^[13] the year is short three days and is fixed on Sunday. With two as well, it lingers two days, and the fixing would be on Monday.

כגון שהיתה שנה שלפניה מעוברת - And the intercalation of a year is thirty [days]. So the fixing should have been on Monday, and because of the eight deficient months it is now delayed, on account of the intercalated month of thirty days, by two more days, and will be on Wednesday, while the molad will be on Thursday at 21 hours; and this is what he asks: But there is still one day! And if you ask: there are two days as well, for the moon is hidden six hours^[14] and will not be seen until Friday! The answer is that we are dealing with a case where last year the molad was at 5 hours on the day before the fixing, for when you add 5 days, 21 hours, 589 parts,^[15] the molad will be at (9 hours) of the day, and it can be seen on Thursday by the people of Eretz Yisrael, and that precedes by only one day. But certainly, if last year the molad was at the beginning of Shabbos, so that this year it is on Thursday at 21 hours and is not seen that day, then we would not make eight deficient, for if so the moon would linger two days. And if you ask: granted that according to Rav Huna, who says that the end clause states it did not seem proper to make more than eight full, eight we do make, and we find it only in an intercalated year, where [the moon] is not seen at all on Thursday until Friday; but on the first clause of the Mishnah, one does not make fewer than four full months, he must explain like Ulla, because one does not make more than eight deficient, so eight we do make, and that is where it is seen on Thursday itself, where last year the molad preceded the fixing. If so, the Mishnah speaks of separate cases!^[16] One can say that the Tanna of our Mishnah set out to teach us all the ways we may change the months from their order: in the first clause he taught that we make eight deficient if last year the molad preceded the fixing, and in the end clause he taught that we make eight full if last year the molad did not precede its day of fixing. And according to what I explained above,^[17] the first and end clauses are set in one manner.

Notes

1. 1. This continues the sugya from the previous amud [Arachin 8b]. The Mishnah taught: “One does not make fewer than four full months in a year, and it did not seem proper [to make] more than eight.” Rav Huna explained: it did not seem proper to the Sages to make more than eight months full. The Gemara asked why not nine, and answers: if so, the new moon would appear three days early.
2. 2. A lunar month, from molad to molad, is 29 days, 12 hours and 793 parts. The calendar therefore normally alternates full months of 30 days with deficient months of 29, and Rosh Hashanah falls on the day of the molad. Each full month beyond that order delays Rosh Hashanah one day past the molad, so the new crescent is seen before Rosh Hashanah.
3. 3. With eight full months, two more than the usual order, Rosh Hashanah is pushed two days past the molad, so the new moon is seen two days before Rosh Hashanah, and yet Rav Huna allows eight.
4. 4. Rav Mesharshiya’s words are brought on the next amud [Arachin 9b], concerning the days on which Atzeres and Rosh Hashanah can fall. An intercalated year is one to which a thirteenth month is added. “The intercalation of a year is a month”: the added month may be made deficient. If last year’s added month was deficient, last Rosh Hashanah came early, and this year’s extra full month balances it.
5. 5. Rav Huna and Ulla give two explanations of the Mishnah. Rav Huna [Arachin 8b] reads it as: no more than eight full months. Ulla (below) reads it as: no more than eight deficient months, which is the reason for the first clause, not fewer than four full months.
6. 6. The first clause of the Mishnah requires at least four full months of thirty days each year; in an ordinary year of twelve months that leaves at most eight deficient months.
7. 7. The opposite problem: each deficient month beyond the usual order brings Rosh Hashanah one day before the molad, so the old, waning moon is still seen after Rosh Hashanah; with nine deficient months, for three days.
8. 8. With eight deficient months, two more than the usual order, Rosh Hashanah comes two days before the molad, and yet Ulla allows eight.
9. 9. Here the case is reversed: last year’s added month was made full, thirty days, half a day longer than a lunar month, which delayed Rosh Hashanah; this year’s extra deficient month balances it (Rashi).
10. 10. The Gemara continues on the next amud [Arachin 9b]: on what do Rav Huna and Ulla disagree? On the length of the intercalated month, whether it is thirty days or simply “a month.”
11. 11. The “fixing” (kevi’ah) is the day on which Rosh Hashanah is set. Hours are counted from the start of the night, so 21 hours into Thursday is the afternoon of Thursday. The crescent cannot be seen close to the molad, so it is first seen on Friday.
12. 12. GaTRaD is a postponement rule: when the molad of Tishrei in an ordinary year falls on Tuesday at 9 hours and 204 parts or later, Rosh Hashanah is postponed. Were it fixed that day, next year’s molad would fall on Shabbos at 18 hours, pushing Rosh Hashanah to Monday, and the year would be 356 days long, with eight full months.
13. 13. Three deficient months beyond the usual order, that is, nine deficient months.
14. 14. The moon is hidden for 24 hours around the molad: for Bavel, six hours of the old moon and eighteen of the new; for Eretz Yisrael, the reverse [Rosh Hashanah 20b].
15. 15. 5 days, 21 hours and 589 parts is what an intercalated year of thirteen lunar months adds beyond whole weeks; adding it to last year’s molad gives this year’s.
16. 16. That is, the two clauses of the Mishnah would be speaking of two different cases.
17. 17. Above: in Tosfos ד"ה מאי שנא תשעה דלא, which the Vilna edition prints at the head of this amud; on this site it stands with the previous amud [Arachin 8b].