Moroni’s first farewell, recorded in Mormon 8–9, was written “four hundred years” after the “the coming of our Lord and Savior” (Mormon 8:6). Notably, this was approximately fifteen years after the battle at Cumorah (see Mormon 6:5). Moroni’s final farewell, contained in the book bearing his own name, was written “more than four hundred and twenty years” after “the sign was given of the coming of Christ” (Moroni 10:1). By this time, nearly thirty-five years had passed since the battle at Cumorah. So Moroni was at least middle-aged by this point and had wandered for many years to escape death at the hands of the Lamanites and also to fulfill the commandments of the Lord (Moroni 1:1–4).
In this book, Moroni opens his treasure box of ecclesiastical, spiritual, and personal records and brings forth some of the greatest written jewels found anywhere in the Book of Mormon. These include instructions for performing priesthood ordinances and conducting the meetings of the Church of Jesus Christ (Moroni 1–6), three personal letters from his father Mormon (Moroni 7–9), and Moroni’s final set of powerful exhortations to the surviving descendants of Lehi (Moroni 10).
Book of Mormon Central, “Why Did Moroni Write So Many Farewells? (Mormon 8:1),” KnoWhy 233 (November 17, 2016).