Reference: While this allusion to “very small means” is so fleeting and general, in the context of other foundational Nephite stories it seems a likely echo of the Liahona. Nephi commented: “And there was also written upon them a new writing, which was plain to be read, which did give us understanding concerning the ways of the Lord; and it was written and changed from time to time, according to the faith and diligence which we gave unto it. And thus we see that by small means the Lord can bring about great things” (1 Ne. 16:29).
Nephi contrasts small (physical) things with great (spiritual) things. Alma makes the identical contrast. By small physical means, such as the plates’ brightness, the Lord brings about great spiritual things, or the “salvation of many souls.” I read this allusion as confirmation that Alma links the plates’ brightness to salvation that following the contents will bring. The brightness is a small thing; the salvation of souls is a great thing.