1) IN WHAT MONTH WAS THE WORLD CREATED?
QUESTION: The Beraisa says that the Chochmei Yisrael count the number of years from Creation in accordance with the opinion of Rebbi Eliezer, who says that the world was created in Tishrei. However, they calculate the Tekufah from Nisan, in accordance with the opinion of Rebbi Yehoshua.
This ruling seems contradictory. How can the Chochmei Yisrael rule like both Rebbi Eliezer, who says that the world was created in Tishrei, and like Rebbi Yehoshua, who says that the world was created in Nisan?
ANSWERS:
(a) RASHI and TOSFOS explain that the Chochmei Yisrael agree with the opinion of Rebbi Yehoshua that the world was created in Nisan. This is evident from the fact that they count the Tekufah according to Rebbi Yehoshua. The calculation of the Tekufah affects the times of the Molad and Birkas ha'Chamah (the blessing recited when one sees the sun at the same position it was in when it was created). The only reason why they rule that the years are counted from Tishrei, like Rebbi Eliezer, is because Tishrei is a more important time due to its status as Rosh Hashanah for various matters (Shemitah, Yovel, Orlah, Ma'aser, etc.), as the Gemara (8a) derives from verses.
The RITVA explains, like Rashi and Tosfos, that the Chochmei Yisrael agree with the opinion of Rebbi Yehoshua. However, the Ritva rules that the Halachah in practice follows the opinion of Rebbi Eliezer even with regard to the calculation of the Tekufah. His basis for this ruling is the fact that Rav (27a) states that the world was created in Tishrei (and Rav has the authority to dispute a Beraisa -- "Rav Tana Hu u'Palig"). For this reason, in the Shemoneh Esreh of Rosh Hashanah we say that "this day is the beginning of Creation," following the opinion of Rav (who rules like Rebbi Eliezer) that the world was created in Tishrei.
(b) RABEINU TAM (27a, cited by Tosfos DH k'Man) says that even Rebbi Yehoshua, who says that the world was created in Nisan, agrees that Hash-m wanted to create the world in Tishrei. This explains why, even according to Rebbi Yehoshua, we say in the Shemoneh Esreh of Rosh Hashanah that "this day is the beginning of Creation": Hash-m planned the Creation to take place in Tishrei. Since Hash-m originally planned to create the world in the month of Tishrei, that month is considered the start of the history of the world. This also explains why the years are counted from Tishrei even though the Halachah follows Rebbi Yehoshua.
(Alternatively, perhaps Rebbi Eliezer agrees with Rebbi Yehoshua that Hash-m planned to create the world in Tishrei but did not actually create it until Nisan. The only argument is whether the Creation, with regard to counting the years, is associated with the time at which Hash-m planned to create the world, or with the time at which He actually created the world. Accordingly, both Rebbi Eliezer and Rebbi Yehoshua agree that the Tekufah is calculated from Nisan, and the only argument is how to count the years. The Halachah effectively follows Rebbi Eliezer since the years are counted from Tishrei.)
(c) RABEINU CHANANEL is not bothered by the contradiction in the ruling of the Chochmei Yisrael. He comments that with regard to matters that pertain to the moon (and the lunar cycle) we count from Tishrei in accordance with the opinion of Rebbi Eliezer, and with regard to matters that pertain to the sun (and the solar cycle) we count from Nisan in accordance with the opinion of Rebbi Yehoshua.
What does Rabeinu Chananel mean? How can the Molad of the moon be calculated from Tishrei (which implies that the moon was created in Tishrei), while at the same time the Tekufah is calculated from Nisan (which implies that the sun was created in Nisan)?
Rav David Metzger, in his annotations to the commentary of Rabeinu Chananel, writes that Rabeinu Chananel seems to maintain that the blessing of Birkas ha'Chamah is not a blessing recited when the sun returns to its initial position. There is no such blessing according to Rabeinu Chananel.
How does Rabeinu Chananel understand the Gemara in Berachos (59b) which says that the Birkas ha'Chamah is to be recited when the "sun is in its Tekufah" ("Chamah b'Tekufasah")? Rabeinu Chananel there records two opinions for what "Birkas ha'Chamah" means. The first opinion is the same as the explanation which Rashi there gives: Birkas ha'Chamah is the blessing recited when the sun returns to the position at which it was created, which is actually the Girsa of our text of the Gemara in Berachos. The second opinion is based on the Yerushalmi (Berachos 9:2). The Yerushalmi says that Birkas ha'Chamah is recited when the sun reappears after not being visible for three consecutive days (due to cloud cover, for example). This is the meaning of "Chamah b'Tekufasah," and not that the sun is in its original position. According to this opinion, the calculation of the Tekufah is entirely unrelated to the blessing of Birkas ha'Chamah.
According to Rabeinu Chananel, the Beraisa here in Rosh Hashanah -- which does not consider it contradictory to count Nisan as the first month for the Tekufah and to count Tishrei as the first month for the Molad -- follows the opinion of the Yerushalmi that no blessing is recited when the sun returns to its original position. (There are authorities who take Rabeinu Chananel's opinion about Birkas ha'Chamah into consideration in practice. The grandson of the Maharal attests that the Maharal did not recite Birkas ha'Chamah with Hash-m's name (Rebbi Akiva Eiger OC 229). Similarly, the Sheyarei Keneses ha'Gedolah (ibid.) writes that his community had a Minhag not to recite Birkas ha'Chamah at all.)
As far as the Molad or Tekufah is concerned, it does not make a difference what month is considered to be the beginning of the year. The world was created in Tishrei, as Rebbi Eliezer says. When the Beraisa says that the Chochmei Yisrael count the Tekufah of the sun from Nisan, it means that the Tekufah of Nisan is considered the first of the four Tekufos of the year. The Tekufah is calculated based on when Tekufas Nisan would have been in the Nisan before Creation (see Rambam, Hilchos Kidush ha'Chodesh 9:3). The Molados, however, are calculated from Tishrei (actually, from when the Molad of Tishrei would have been for the Tishrei of the year before the Tishrei of Creation; see TOSFOS 8a, DH li'Tekufas).
This approach also answers a question of Tosfos earlier (8b). Tosfos asks how Rebbi Yehoshua and Rebbi Eliezer can argue about when the sun and moon were created. It is obvious that they were created in Nisan, because astronomical factors and calculations prove that had they been created in Tishrei, the sun and moon would be in different places than they are now. How can Rebbi Yehoshua argue about that? The answer is that their dispute is unrelated to the actual time of the Molad and Tekufah.
Why, though, should the Tekufah be calculated from the Nisan before Creation, extrapolating back from Tishrei? Why is the Tekufah not simply calculated from Tishrei, when the world was created?
The RAN asks this question (3a of the pages of the Rif). He explains (as does the Mefaresh on the Rambam, Hilchos Kidush ha'Chodesh 9:3) that Nisan is a more preferable time from which to calculate the Tekufah because the sun shines more brightly at that time of year and the year's produce begins to grow.

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