Maaseh Rav Siman 42
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
בחזרת הש"ץ יאמר הש"ץ קודם התפלה ה' שפתי ולבסוף יהיו לרצון:
Sefaria Community Translation
In the ḥazzan’s repetition (of shemona esrei) the ḥazzan says prior to the prayer ‘Hashem Siftai’ and at the end ‘Yehyu L’Ratzon’: