S. Kent Brown has made a very perceptive study of Alma’s sermons, noting that they tend to have echoes of Alma’s transformational conversion experience. Specifically concerning this verse, he notes:
“Alma’s soliloquy in chapter 29 also exhibits reminiscences of his three-day experience. First, he wishes that he were an angel and, like the angel of the Lord who confronted him, he wishes he could “go forth and speak … with a voice to shake the earth, … as with the voice of thunder” (Alma 29:1-2). The descriptions of the appearance of the angel of the Lord to Alma and his friends are compelling. In his own words, Alma recounted that
“God sent his holy angel to stop us by the way. And behold, he spake unto us, as it were the voice of thunder, and the whole earth did tremble beneath our feet” (Alma 36:6-7).
The account from other witnesses says that
“the angel of the Lord appeared unto them; and he spake as it were with a voice of thunder, which caused the earth to shake upon which they stood” (Mosiah 27:11).
The similarities cannot be missed. They combine mention of the angel with reference to his thundering voice and the resulting earthquake.”
(S. Kent Brown. “Alma’s Conversion: Reminiscences in His Sermons.” In: Monte S. Nyman and Charles D. Tate, Jr., eds. Alma, the Testimony of the Word [Provo: BYU Religious Studies Center, 1992], 149.)
As noted in this commentary following Mosiah 27:11, the imagery of “voice of thunder” in this verse, and particularly the “voice to shake the earth” in verse 1 have an even greater connotation in Alma’s Mesoamerican context. This is not simply a verbal imagery, but a reminiscence of the physical event, and the particulars of that physical event were structured to highlight the event as belonging to the realm of the sacred. The voice of thunder and the shaking of the earth were elements that marked the sacred in Mesoamerica.