Mormon takes a small deviation from his record of the wars to note that the city of Jashon was “near the land where Ammaron had deposited the records.” Mormon 1:3 informed us that they were deposited in the hill Shim. Mormon was to take the records from the hill when he was twenty-four. In the Nephite year 345, Mormon would have been thirty-five. Did he not obey the command of eleven years earlier?
Although we cannot know for certain, it is probable that he did retrieve the current Nephite record when he was twenty-four, as instructed. He forgot to mention it in the correct chronology, but when he got to this point in the record, he realized that he had not made it clear that he had taken the record from that hill. Therefore, he inserts that information here. It is the right location, but the wrong time. The location simply reminded Mormon that he needed to clarify that he had, and was keeping, the record according to the promise made to Ammaron.
It is also important to note that he says, “upon the plates of Nephi I did make a full account of all the wickedness and abominations; but upon these plates I did forbear to make a full account.” Mormon is speaking of two sets of plates. The first, upon which he wrote the “full account,” was the current Nephite record. It was not the full archive, as will be clear in Mormon 4:23, when he again goes to retrieve records from the hill Shim.
The designation of “upon these plates,” is the abridgment that we know as the Book of Mormon, including the book of Mormon where he is recording his own history with the less than full account of the Nephite wickedness.