Question: If one reciting the Amida prayer has concluded the “Sim Shalom” blessing and has begun reciting the following verse of “Yihyu Le’Ratzon” as the Chazzan begins the recitation of the Kedusha (“Nakdishach Ve’Na’aritzach”), may the individual praying interrupt his own prayer in order to answer Kedusha and Amen to the blessings being recited by the Chazzan or may he not interrupt his prayer at all?
Answer: Clearly, when one is in the midst of reciting a blessing, one may not interrupt in the middle of the blessing for any matter, not even to answer Amen to a friend’s blessing nor to answer Kaddish or Kedusha.
Nevertheless, once one concludes the “Sim Shalom” blessing of the Amida prayer and has recited the verse “Yihyu Le’Ratzon Imrei Fi Ve’Hegyon Libi Lefanecha, Hashem Tzuri Ve’Go’ali,” one will be in the midst of reciting the “Elohai Netzor” section and no longer retains the law of one who is standing in the middle of a blessing. At this point, one may interrupt to answer words of holiness. Thus, one may pause for a moment to answer the Kedusha being recited by the Chazzan and congregation.
Hagaon Rabbeinu Yosef Haim writes in his Sefer Ben Ish Hai that from the moment one recites the “Yihyu Le’Ratzon” verse, one may answer any words of holiness including answering Amen to blessings one hears. The basis for his opinion stems from the words of Maran Ha’Chida in his Kesher Gudal who rules likewise in accordance with the ruling of the Turei Zahav. Hagaon Rabbeinu Ben-Zion Abba Shaul zt”l rules likewise.
On the other hand, Maran Rabbeinu Ovadia Yosef zt”l infers from the words of Maran Ha’Shulchan Aruch that the Halacha does not follow the above opinion. Only answering to Kedusha, i.e. reciting the verses of “Kadosh, Kadosh” and “Baruch Kevod Hashem Mi’mekomo”, is permitted after reciting the “Yihyu Le’Ratzon” verse. It is likewise permissible to answer the first five Amens of Kaddish at this point. Answering Amen to any blessing one hears at this point, however, is forbidden.
The proof to this is that Maran Ha’Shulchan Aruch writes that one who is accustomed to reciting supplications (i.e. personal requests and prayers one inserts at the conclusion of the Amida prayer, within the “Elohai Netzor” section) and hears Kaddish or Kedusha should shorten his prayers and if one does not shorten one’s prayers, one may interrupt “the way one would interrupt during the recitation of the blessings of Keri’at Shema.” Based on the words of Maran, the law of one in the midst of the “Elohai Netzor” section is equal to the law of one in the midst of reciting the blessings of Keri’at Shema. The Halacha is well-known that within the blessings of Keri’at Shema, one may not interrupt in order to answer Amen to blessings. One may likewise not recite the entire text of the Kedusha beginning with “Nakdishach Ve’Na’aritzach” nor may one answer the final verse of the Kedusha, “Yimloch Hashem Le’Olam”. Rather, one may only answer the first five Amens of Kaddish and the verses of “Kadosh, Kadosh” and “Baruch Kevod Hashem” of the Kedusha at this point. If so, the same applies within the “Elohai Netzor” section of the Amida and one may not answer Amen to blessings in the midst of reciting it.
Indeed, many great Acharonim interpret the opinion of Maran Ha’Shulchan Aruch that halachically speaking, the only things one may interrupt to answer within the “Elohai Netzor” section of the Amida are the verses of “Kadosh, Kadosh” and “Baruch Kevod Hashem” of the Kedusha and the first five Amens of Kaddish. Furthermore, when answering “Amen Yehe Shemeh Rabba” at this point, one may only do so until the words “Ul’almei Almaya Yitbarach” and not continue until the words “Da’amiran Be’Alma” as one would usually.
Summary: When one concludes reciting the “Yihyu Le’Ratzon” verse following the conclusion of the “Sim Shalom” blessing of the Amida, one may only interrupt to answer the first five Amens of Kaddish and the verses of “Kadosh, Kadosh” and “Baruch Kevod Hashem” of the Kedusha.