1 Nephi 19:2

And I knew not at that time when I made them, that I should be commanded of the Lord to make these plates; wherefore, the record of my father, and the genealogy of his fathers, and the more part of all our proceedings in the wilderness, are engraven upon those plates of which I have spoken; wherefore, the things which transpired before that I made these plates, are, of a truth, more particularly made mention upon the first plates.

When I first made those plates, I didn’t know the Lord would command me to make these other plates. My father’s record, his family history, and most of what happened to us in the wilderness are carved on those first plates. So the things that happened before I made these plates are written in more detail on the first plates.

When I first made those plates, I didn’t know the Lord would ask me to make this second set. So on the first plates I wrote about my father, our family history, and most of what happened in the wilderness—everything before I made these new plates.