According to Daniel Ludlow, the statement in Mosiah 1:4 that "Lehi . . . having been taught in the language of the Egyptians therefore he could read these engravings [on the brass plates of Laban]" quite clearly indicates that these plates were written in the Egyptian language (or script). Thus they were almost certainly not started until after the flood and the tower of Babel, as there was no "Egyptian" language before those events. The brass plates were probably not started until after the Israelites went down into Egypt in the days of Joseph, although the writers on these plates may have had access to records which had been written earlier. Other evidences supporting this thesis are: (1) Laban "was a descendant of Joseph, wherefore he and his fathers had kept the records" (1 Nephi 5:16); (2) the great prophecies "of Joseph, who was carried into Egypt . . . are written upon the plates of brass" (2 Nephi 4:1, 2); and (3) the plates of brass also contained "the five books of Moses" (1 Nephi 5:11). Other writers continued recording on these plates "even down to the commencement of the reign of Zedekiah, king of Judah" (1 Nephi 5:12). [Daniel Ludlow, A Companion to Your Study of the Book of Mormon, p. 173]
What might be implied here is that: (1) if the brass plates were a record of the lineage of Joseph, then Joseph was not only their originator, but made them a part of his privileged position near Royalty in Egypt; (2) perhaps Moses, who was royally trained in the Egyptian language, continued to use the brass plates at some time in his life; and (3) perhaps when Nephi was commanded by the Lord to return for the plates of brass he was (as in many other ways), emulating a similar assignment given by the Lord to Moses (that is, to return to his homeland from Midian -- which is the same location as the valley of Lemuel -- and claim the brass plates from high government officials who had them in their possession). [Alan C. Miner, Personal Notes] [See the commentary on 1 Nephi 3:3]
“For He Having Been Taught in the Language of the Egyptians Therefore He Could Read These Engravings”
Curiously, the brass plates of Laban were written in Egyptian Hieroglyphs. One could ask why this language, rather than Hebrew, was used to permanently record the sacred scriptures. According to Clay Gorton, it is likely that there were some translations by Israelite scribes from Hebrew into Egyptian before Lehi's time as it was the language of culture of the day. Nevertheless, it is improbable that the voluminous text of the brass plates would have been translated from Hebrew into Egyptian. In the first place, the Israelites did not hold the Egyptians, from whom they had escaped bondage, in high regard. Their own tongue was considered by many to be the language of God. Even today, orthodox Jews give the original language text of their scriptures a position of high esteem. So why did they have their scriptures, which were inscribed on metal plates to preserve them against the ravages of time, written in Egyptian? Of course, inscribing on metal plates was painstaking and tedious, and a shorthand method would be highly desirable. (Jacob, the brother of Nephi, complained of the difficulty of engraving upon plates. See Jacob 4:1-3) Clearly, one of the reasons they were written in Egyptian on the brass plates was to minimize the writing process. If saving space were the only reason to have written in Egyptian, that would have been an adequate reason. However there may have been yet a more fundamental reason why they were written in Egyptian. Moses, who wrote the first volumes of scripture that were preserved by the Israelites, was an Egyptian. Egyptian was his native language. True, he undoubtedly knew Hebrew, and probably learned it as an infant from his mother who was employed as his nurse. Yet he lived in the house of the Pharaoh and held high offices in Pharaoh's court. . . . Moses may well have written the Pentateuch on metal plates in Egyptian--both to minimize the engraving process and because of the ease of writing in his native language. Were this the case, the prophets who followed him would have had to learn Egyptian in order to read the sacred record. Their ability to read Egyptian and their deference for Moses could have impelled succeeding prophets to record their scriptures in Egyptian. [H. Clay Gorton, The Legacy of the Brass Plates of Laban, p. 19] [See the commentary on 1 Nephi 3:3]
Mosiah 1:4 Having been taught in the language of the Egyptians therefore he could read these engravings ([Illustration]): Anthon Transcript and Egyptian Demotic compared, From Language of the Book of Mormon, by I.A. Smith [Glenn A. Scott, Voices from the Dust, p. 64]
Mosiah 1:6 O my sons, I would that ye should remember that these sayings are true, and also that these records are true ([Illustration]): A Maya father exhorts a son thirteen hundred years ago much as Benjamin did his sons nine hundred years before that (see Mosiah 1:2-8). Notice what appears to be a book next to the young man, which reminds us of Benjamin's emphasis to his princes on the importance and significance of mastering the records. [John L. Sorenson, Images of Ancient America, p. 75]