As Nephi writes, he marks the progress of time and movement through his narrative with the phrase “and it came to pass.” At times, when moving quickly through certain events, he will have three or four sentences in a row that begin with “and it came to pass.” Here we have a section that begins with “and it came to pass.” When this little section ends, the next starts again with “and it came to pass.”
Nephi was writing at a time prior to the use of punctuation. As Joseph dictated the translation, there was no indication of punctuation. The compositor did a pretty good job of making it easier to read by adding punctuation, but what could be done during Nephi’s day? In Nephi’s day, he could use verbal markers that would clue the listener or reader that a new thought, or section, had begun. That is the function of “and it came to pass” in the Book of Mormon. It occurs frequently when Nephi records history. In 2 Nephi, when Nephi is discussing prophecy, it is very rare.
Verse 12, which speaks of the family not making fire during their journey appears to be an aside that Nephi made which was not planned. It was triggered by making fire for the forge. That is not at all like making a fire for food, but it triggered his remembrance that he hadn’t explained why they had eaten raw meat. We can tell that it is an aside because it is out of timeframe, and out of the context of the rest of this text.