The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes that when one responds to Barechu in the Friday night Arbit service, he receives the "Ru’ah" portion of the extra soul with which we are endowed on Shabbat. The "Neshama" aspect of the extra soul descends upon a person later during the Arbit service, before the Amida, during the recitation of "U’fros Alenu Sukat Shelomecha."
The question arises, if a person prays privately, in which case Barechu is not recited, how can he receive the "Ru’ah" aspect of the extra soul? Is there any other means available through which a person can access the additional "Ru’ah"?
The Ben Ish Hai addresses this question (listen to audio recording for precise citation) and cites a Berayta (Talmudic passage) which describes the angels reciting Barechu in the heavens. One angel arises and proclaims, "Barechu Et Hashem Ha’meborach," and the others respond, "Baruch Hashem Ha’meborach Le’olam Va’ed" (just as the Hazzan and congregation recite Barechu in the synagogue). The Ben Ish Hai writes that by reciting this Berayta in place of Barechu, one can – to one extent or another – be considered as having recited Barechu. Thus, according to the Ben Ish Hai, whenever a person must recite Arbit privately, even during the week, he should recite this Berayta in place of Barechu. On Friday, this recitation has the effect of bringing upon oneself the "Ru’ah" of the extra soul of Shabbat.
Hacham Ovadia Yosef, however, in his Halichot Olam, rules that one should not recite this Berayta in place of Barechu. Reciting this Berayta requires saying the passages "Barechu Et Hashem Ha’meborach" and "Baruch Hashem Ha’meborach Le’olam Va’ed" with God’s Name. Hacham Ovadia notes that this might violate the prohibition of reciting God’s Name in vain. These declarations were instituted to be recited only in the presence of a Minyan, and therefore reciting them in private is, seemingly, forbidden. As such, even if we accept the premise that reciting this Berayta will have the effect of bringing upon oneself the extra "Ru’ah," it runs the risk of causing a serious Torah violation. Hacham Ovadia therefore writes that one make every effort to attend a Minyan for Arbit on Friday night, but if one must pray privately, he should not recite the Berayta cited by the Ben Ish Hai.
Summary: One must make every effort to attend a Minyan for the Friday night Arbit service, as one aspect of the "extra soul" of Shabbat is received through the recitation of Barechu, which cannot be recited without a Minyan.
