Mormon would turn fifteen years of age sometime in the year A.D. 326 as shown above. The Lord visiting him (v. 15) reminds us of Joseph’s first vision in about the same time period of his life (see JS–History 1:7–20). Joseph Smith was in his fifteenth year but was only fourteen years of age. Mormon was fifteen years of age, but was in his sixteenth year as will be shown later.
Mormon being forbidden to preach to the people reminds us of the Prophet Isaiah. He was instructed by the Lord to not warn those of Northern Israel, but to work among the faithful disciples (see Isaiah 8:11–16; 2 Nephi 18:11–16). Mormon also remained among the Nephites, and would certainly have worked with the remaining few faithful disciples who were among the Nephites.
The work of the Gadianton robbers continued to prosper (Mormon 1:18), but the Lord again caused that the treasures that had been hid up in the earth and not unto the Lord to become slippery (see Helaman 13:18–23; 31–34). In addition, we would learn that the sorceries, witchcraft, and magic (Mormon 1:19), the work of Satan and his counterpart to the priesthood, were also flourishing. The prophecies of Abinadi and Samuel the Lamanite do not specifically mention sorceries, witchcraft, and magic, but Abinadi does warn the Nephites to repent or be destroyed.
8 And it shall come to pass that except they repent I will utterly destroy them from off the face of the earth; yet they shall leave a record behind them, and I will preserve them for other nations which shall possess the land; yea, even this will I do that I may discover the abominations of this people to other nations. And many things did Abinadi prophesy against this people. [Mosiah 12:8]
Samuel warned of their treasures becoming slippery, as mentioned above, and also of the destruction that was to come before four hundred years had passed away after Christ was born (see Helaman 13:8–10). Both prophets gave many prophecies that were not included in Mormon’s abridgment, and perhaps Mormon had reference to some of these (see Mosiah 1 2:8 quoted above, and Helaman 14:1).