The final section of the Arbit service before the Amida concludes with the Beracha, "Shomer Et Amo Yisrael Mi’kol Dabar Ra La’ad, Amen." If a person finishes this Beracha before the Hazan, should he recite "Amen" along with the Hazan as the Hazan completes the Beracha?
The Ben Ish Hai (Rabbi Yosef Haim of Baghdad, 1833-1909) writes that answering "Amen" to this Beracha would constitute a "Hefsek" (interruption) in between one’s own Beracha and the Amida. In his view, then, one should not answer "Amen" to the Hazan’s recitation of the Beracha, "Shomer Et Amo Yisrael…" Others, however, including Hacham Ben Sion Abba Shaul (Israel, 1923-1998) and Hacham Ovadia Yosef, disagreed, and held that one should, in fact, answer "Amen" to this Beracha. This is indeed the Halacha.
This ruling applies on Friday night, as well, when the section before the Amida concludes with the Beracha, "Ha’pores Sukat Shalom Alenu Ve’al Kol Amo Yisrael Ve’al Yerushalayim." One who finishes reciting this Beracha before the Hazan should ensure to answer "Amen" to the Hazan’s Beracha. Rav Haim Palachi (Turkey, 1788-1869), in his work Kaf Ha’haim, bemoans the fact that many people begin reciting "Ve’shameru Beneh Yisrael" immediately after the Hazan completes this Beracha, before answering "Amen." He likewise observed that people often begin reciting "Modim" immediately after the Hazan recites the Beracha, "Ha’mahazir Shechinato Le’Sion," without answering "Amen." Answering "Amen" to Berachot is an important obligation, Rav Haim Palachi writes, and one must therefore ensure to answer "Amen" before proceeding to "Modim" or to "Ve’shameru." He relates in this context that a certain Sadik once beheld a dream in which he was told that the time for the final redemption had arrived, but its arrival was delayed because people did not pray with proper concentration. The dream pointed specifically to the fact that people were lax in answering "Amen" to Berachot, which demonstrated an inappropriately casual attitude toward Tefila. It thus behooves us to ensure to answer "Amen" to Berachot, including the Berachot discussed above.
Summary: One should answer "Amen" to the Hazan’s repetition of the Beracha, "Shomer Et Amo Yisrael Mi’kol Dabar Ra La’ad" at Arbit, as well as the Beracha of, "Ha’pores Sukat Shalom Alenu Ve’al Kol Amo Yisrael Ve’al Yerushalayim" on Friday night.
