Tefillah on Shabbos
Why do we say Elokai Nitzor at the end of all Shabbos tefillos if we are not allowed to ask for personal bakashos on shabbos and elokai is a tefillah for personal requests?
This question was asked by the Or Zarua [one of the Rishonim]. In his sefer Or Zarua Vol. 2 Siman 89, in the halachos of Motzai Shabbos he explains that this is permitted because it is a regular part of the davening, so we don’t change it even on Shabbos. This idea is based on the Talmud Yerushalmi in the 15th Chapter of Shabbos that uses this rational to explain why say regular Birchat Hamazon on Shabbos even though it includes supplications and requests.