Translation: The building image would be familiar to anyone who lived in a culture where permanent buildings were erected, so this reference is not out of place in the Mesoamerican setting in which this commentary sees the Book of Mormon. However, once again the specific language is so evocative of the New Testament that it must have served as the translation model for the similar concepts:
Matthew 7:24-27
24 ¶ Therefore whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his house upon a rock:
25 And the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock.
26 And every one that heareth these sayings of mine, and doeth them not, shall be likened unto a foolish man, which built his house upon the sand:
27 And the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell: and great was the fall of it.
Of course the idea that they should be build “upon the rock of our Redeemer” is also evocative of another use of the phrase “upon this rock:”
Matthew 16:18
18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
In this case, however, the presence of the similar phrase is not sufficient to be more than a coincidence. Of course Joseph would also be familiar with this passage but the specific context of the building suggests that the previous set of verses from Matthew 7 is the literary model for the language used in this verse.
Hel. 5:13
13 And it came to pass that these were the words which Helaman taught to his sons; yea, he did teach them many things which are not written, and also many things which are written.
Redaction: Mormon formally marks the end of his inserted passage. He now returns to his own synopsis of events. Structurally, Mormon presented the idea that there would be a missionary effort. He then inserts a discourse that is out of place in time, and then returns to the missionary journey. Mormon clearly sees this inserted charge from Helaman to his sons as intimately connected with this missionary journey. In what way?
The charge from Helaman did include one reference to a missionary experience when he evoked the memory of Amulek. However, for Mormon it is not the presence of the missionary name that was important, but rather the overall theme. As noted at the beginning of the section the leitwort of the entire passage is remember. That is the message that Mormon is emphasizing. In Mormon’s authorial intent, he sees the ills of Nephite society as begin cause by their departure from the gospel. Therefore remembering the covenants of the father is the essence of the missionary journey. Nephi and Lehi are to preach to the people so that they too will remember, and that they will repent and return to the gospel that they have abandoned.