By HaRav Shimon Anshin shlit”a
A. The Talmud Yerushalmi (Shabbos 15:3) writes that it is prohibited to appeal to Hashem for one’s needs on Shabbos. And even though this prohibition it is not mentioned in the Talmud Bavli, and there is no such ruling to be found in the Rambam or Shulchan Aruch, nevertheless, some Rishonim together with the Tur (siman 188) and the Achronim, do in fact bring such a ruling.
The following are a few reasons brought by the Poskim as to why appealing to Hashem for one’s needs on Shabbos is forbidden:
1. That one should not come to cry on Shabbos (Ra”n).
2. That one has to consider Shabbos to be lacking nothing – i.e. nothing is left incomplete on Shabbos (Korban Haeida).
3. That one should not come to speak words of weekday matters (Divrei Chol) on Shabbos (Questions and Answers of the Yaabetz)
Now, even though there is no Biblical or Rabbinical prohibition against making such requests on Shabbos, doing so then would nevertheless be considered a transgression of the rulings of the Chachamim.
So, on the one hand then, it appears by the statement of the Yerushalmi that there is no license to appeal for one’s physical or spiritual needs on Shabbos, yet on the other hand, we find many prayers on Shabbos that do deal specifically with requesting one’s needs. In this form then, the Poskim rule that it is in fact permissible to make requests for one’s needs. And so,
B. Any established prayers that contain requests for one’s needs, have no issue in regards to the abovementioned prohibition, for example:
1. “…Ro’einu, Tzo’neinu, Parnas’einu …” which is found in Birkas Hamazon dealing specifically with one’s livelihood (Yerushalmi).
2. “…Elokay Netzor …” which is found at the end of the Shemonah Esrei (Ohr Zaruha part 2,88)
3. “…Ha’Rachaman …” which has numerous requests found at the end of Birkas Hamazon.
C. Prayers established specifically for Shabbos. Some examples are:
1. “…Berich Shemay …” extracted from the Zohar Hakadosh said during the opening of the Ark.
2. “…Ribon Ha’Olamim …” said after “Shalom Aleichem” on Shabbos night has many requests for one’s needs and is too allowed because it is considered an established prayer (Questions & Answers – Torah Lishma & Rav Pe’alim part 2, 46).
3. “…Ye’heh Ra’avah …” in the Shabbos Zmiros also contains requests for one’s needs. However, in this particular case, there are those that hold it is NOT permissible to ask for one’s needs over here, while others allow it.
D. All prayers that are NOT in the form of supplications or requests for mercy, but are rather in the form of Brochos are permissible. Some examples are:
“…Yekum Purkan …” or Mishebeirachs that are made on behalf of the community after the Torah reading.
E. Prayers for Klal Yisrael as a whole such as:
“…Zochreinu L’Chayim…” or “…mi Chamocha…” on Rosh Hashanah or Yom Kippur.
As this is a translation of the original Hebrew, if you are unclear on any of the Laws outlined herein in any way whatsoever, please consult with a Posek (Halachic Authority).