Halakhic Positions of Rav Joseph B. Soloveitchik
by R. Aharon Ziegler
The Gemara Pesachim (56a) records, that Yaakov Avinu recited the phrase of “Baruch shem kevod malchuto le’olam “(Blessed be the name of His kingdom forever) upon hearing the declaration of Shema by his sons. However, since the phrase was not included by Moshe Rabbeinu in the Shema section of the Torah (Devarim 6:4-9), the Sages enacted that we should only recite it quietly. Rav Soloveitchik maintained, that the restriction on reciting Baruch Shem aloud applies only to a Minyan davening together, but an individual praying alone may recite the phrase Baruch Shem aloud within his restriction of Shema.
The explanation of the Rav’s view is that responsively reciting Baruch Shem aloud after the Shema declaration would be a form of angelical Kedushah, and we do not have permission to use this format if the words are not found in the written Torah. The Midrash Devarim Rabbah (2:36) explains that we do not recite Baruch Shem publicly because Moshe overheard the Malachim (angels) reciting it as a Shirah, and to recite it publicly would be tantamount to theft from the king’s palace. If Baruch Shem would be recited aloud and responsively, it would be unauthorized theft of the angel’s Keddushah. Since Baruch Shem is not recorded in the written Torah, we have no permission to recite it as Kedushah.