- Shabbat and Holidays
- Rosh Chodesh
The unique nature of Rosh Ĥodesh must find expression in our prayers. After all, the Sages instituted our prayers in place of the offerings, and the Torah commands us to bring a musaf offering on Rosh Ĥodesh. Therefore, the Sages prescribed that we recite the Ya’aleh Ve-yavo prayer, in which we beseech God to remember us for good on Rosh Ĥodesh. They inserted it in the berakha of Retzei because that is where we ask God to restore the divine service to the Holy Temple, making it an appropriate place to mention Rosh Ĥodesh; once the divine service is restored we will be able to offer the musaf of Rosh Ĥodesh. One who forgets to recite Ya’aleh Ve-yavo in Shaĥarit or Minĥa must repeat the Amida (Shabbat 24a).
If one realizes that he forgot to recite Ya’aleh Ve-yavo immediately after completing the berakha of Retzei, he should insert Ya’aleh Ve-yavo there, and then continue with Modim. If one already began Modim, but remembered before starting to take three steps back at the end of the Amida, he should return to the beginning of Retzei and continue from there until the end, inserting Ya’aleh Ve-yavo in its proper place. This is true only regarding Shaĥarit and Minĥa; if one forgot to recite Ya’aleh Ve-yavo at Ma’ariv, he should not repeat any part of the Amida, unless he remembers before reciting God’s name at the conclusion of Retzei. Ma’ariv is different from the other prayers because the beit din did not sanctify the new month at night. Thus, even though one should recite Ya’aleh Ve-yavo in Ma’ariv, he should not repeat the Amida, or even one berakha, in order to recite it (Ber. 29b, 30b; sa 422:1).
 If one is unsure whether he recited Ya’aleh Ve-yavo in Shaĥarit or Minĥa, he should assume that he did not, and thus he must repeat the Amida in order to do so. However, if, earlier in the course of his prayers, he intended to add Ya’aleh Ve-yavo, but he is later uncertain whether he actually did so, he should assume that he did recite it, and thus he need not repeat the Amida (mb 422:10). One who forgot to recite Ya’aleh Ve-yavo in the final Minĥa service of Rosh Ĥodesh should recite the Amida twice in Ma’ariv, stipulating beforehand that if he is not obligated to recite the Amida twice, his second Amida should be considered a voluntary prayer (sa 108:11; Peninei Halakha: Prayer 18:10).
Customarily, the gabbai (sexton) calls out, "Rosh Ĥodesh" or "Ya’aleh Ve-yavo" prior to the Amida of Ma’ariv (sa 236:2). In Shaĥarit, however, one may not interrupt between the berakha of Ga’al Yisrael and the Amida. Therefore, it is customary to bang on the podium twice, wordlessly reminding the congregants to insert Ya’aleh Ve-yavo. In addition, some have a custom to raise their voices slightly upon reaching the words Ya’aleh Ve-yavo in the silent Amida to remind others to recite it (Sheyarei Knesset Ha-gedola). Another suggestion is for the ĥazan to end the berakha of Ga’al Yisrael using the unique Rosh Ĥodesh tune, in order to remind the people to recite Ya’aleh Ve-yavo.