According to Brant Gardner, the effect of reading the scriptures of the brass plates had a profound effect on Lehi, sufficient to induce prophetic vision: "And now when my father saw all these things [on the plates of brass], he was filled with the Spirit, and began to prophesy concerning his seed" (1 Nephi 5:17). While the scriptures may have a similar effect on all of us--to inspire us to greater receptivity to the things of the spirit--the brass plates had a particular strength for Lehi due to their relationship to his ancestry [and to his posterity]. . . . Note also that it was not only Lehi who searched the brass plates. Nephi himself is involved in understanding the import of the records which he gave so much to obtain (v. 21 "we had obtained the records . . . and searched them . . .)
We have the information about the brass plates because we have the Book of Mormon. Is it possible that we have the Book of Mormon because Lehi and Nephi had the brass plates? In other words, did the brass plates provide many of the models used in the development and transmission of the Book of Mormon texts up to the time of Mormon's compilation?
(1) The first obvious similarity is the preservation of the sacred text on metal. . . . From a physical standpoint, the brass plates provided a model for the Nephite plates.
(2) The language of the Nephite plates may also have been influenced by that of the brass plates. There is reference to the necessity of having an understanding of Egyptian to be able to read the brass plates (Mosiah 1:4). If they were written using any form of Egyptian, the decision to use Egyptian, or later reformed Egyptian on the Nephite plates would be clearly taking a model from the brass plates.
(3) The brass plates contained a collection of the words of individual prophets. This was also the case in the Nephite plates; the tradition was kept that each person writing on the plates would contribute their "book." (The reader should note that this tradition was departed from in the book of Omni.) The construction of a canon which consisted of the collected works of individuals follows the brass plates.
(4) The brass plates were kept by the lineage of Joseph. . . . That model, of having a set of scriptures related to a particular lineage can be seen with the Nephite records.
As a matter of note, the dual transmission line of the large and small plates may also have some connection to the model of the brass plates. Clearly the brass plates followed a lineal transmission, and were known to the members of that lineage. Just as clearly, however, there were other sets of scripture available (if only that of the line of Judah). We therefore have a model of multiple sets of scripture which could serve for the large/small plates distinction. Since the large plates became the politically transmitted set, there may have been precedence in Jerusalem for an "official" record which followed the political power, with the brass plates representing the smaller lineage tradition. That conceptual model fits directly with the known transmission lines of the large and small plates in the Book of Mormon. [Brant Gardner, "Book of Mormon Commentary," 1Nephi/1Nephi5.htm, pp. 8-9]