Note that the main story in the book of Mosiah is told in the third person rather than in the first person as was the custom in the earlier books of the Book of Mormon. The reason for this is that someone else is now telling the story, and that “someone else” is Mormon. With the beginning of the book of Mosiah we start our study of Mormon’s abridgment of various books that had been written on the large plates of Nephi. (3 Nephi 5:8-12.) The book of Mosiah and the five books that follow—Alma, Helaman, 3 Nephi, 4 Nephi, and Mormon—were all abridged or condensed by Mormon from the large plates of Nephi, and these abridged versions were written by Mormon on the plates that bear his name, the plates of Mormon. These are the same plates that were given to Joseph Smith by the angel Moroni on September 22, 1827.