Raphael Grunfeld’s summary of why there are two days of Rosh Hashanah even in Eretz Yisrael, and how these two days are different from the two days of the other Yomim Tovim kept only in the Diaspora (“Two Days Rosh Hashanah, Eruvin and Eggs,” September 2, 2021), is very important. Nevertheless, there is one clarification I would like to add.

Grunfeld explained how, in contrast to the two days of Yom Tov outside of Israel (which was based on not knowing when the first of the month was declared in Jerusalem), the two days of Rosh Hashanah being kept even in Jerusalem was based on a decree made after an aspect the Temple service was adversely impacted when witnesses didn’t arrive to testify that they had seen the new moon until very late in the day. In order to avoid this from happening again, testimony would no longer be accepted after the second Tamid offering was brought. Yet, even though they knew that the next day would be Rosh Hashanah, the Yom Tov restrictions were maintained for the remainder of the day. In other words, they kept two days of Rosh Hashanah not because they weren’t sure which day would be Rosh Hashanah, but because they decreed that both days should be Rosh Hashanah. He then added that after the Temple was destroyed, when there was no longer a concern that the Temple service would be impacted, they resumed accepting testimony about the new moon the entire day. Which leads to the question of why they still kept two days of Rosh Hashanah in Israel. It makes sense for them to have kept this in the Diaspora, but why in Israel too?

In order to answer this, Grunfeld writes, “The Babylonian rabbis who came to Israel applied the same decree [that they had made for the Diaspora] to the Land of Israel.” The implication is that there was no inherent reason to keep two days of Rosh Hashanah in Israel, but it was instituted by the Babylonian rabbis in order to maintain consistency with their brethren in the Diaspora.

Aside from our current situation, where there is no consistency for the other Yomim Tovim, indicating that is not a concern, the Talmud itself says otherwise (Beitza 5b). As Rashi explains there, even though they once again accepted testimony the entire day (and would count the first day of Rosh Hashanah as the first day of the month), they still kept two days of Rosh Hashanah. It was not because it was reinstated by the Babylonian rabbis at a later date; rather, two days of Rosh Hashanah were kept in Jerusalem after the destruction just as they had been before the destruction.

For further clarification, it must be pointed out that there is another possibility (see Rashba), depending on whether a change was made (or would have been made) after the calendar was set by calculation rather than by testimony. Some are of the opinion that there was a point in time when only one day was kept (or would have been kept) after the set calendar was established, if not for the message from the Babylonian rabbis that they should maintain the traditions of their ancestors. But this “decree” was not made in order to maintain consistency with their brethren in the Diaspora, but for the same reason those in the Diaspora were told to continue to keep two days for all Yomim Tovim; they should keep doing what they had been doing, in case it was no longer possible to maintain a set calendar. They had been keeping two days of Rosh Hashanah, so were told to keep doing so.

Although this could be what Grunfeld meant, it wasn’t clear from his article. And, as mentioned, Rashi’s approach wasn’t referred to at all. Wishing all a blessed new year, when hopefully we will resume accepting testimony about the new moon in Jerusalem!