S. Kent Brown’s perceptive study of Alma’s sermons notes that they all have echoes of Alma’s transformational conversion experience. On this verse, he comments:
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.
As noted in the commentary accompanying Mosiah 27:11, the “voice of thunder” in this verse and particularly the “voice to shake the earth” in verse 1, have strong cultural connotations in a Mesoamerican context. This description is not just a literary image but a memory of the actual event, whose details were shaped to stress the sacredness of the event. The voice of thunder and the shaking of the earth were elements that marked the sacred in Mesoamerica.