Narrative: Likely Nephi’s brothers knew nothing about his recent vision and especially Yahweh’s promise that he would rule over them. (Nephi had probably learned from Joseph’s unpleasant story that such news was not greeted warmly.) It also seems unlikely that Nephi had told them of his impassioned commitment to Lehi, based on his faith that Yahweh would prepare the way.
Nephi’s oath—”As the Lord liveth, and as we live”—was a powerful vow. Oath-making is a serious occasion in a world where agreements are primarily oral rather than written. (See commentary accompanying 1 Nephi 4:31–45.) Although the Middle East cultures of Nephi’s day were literate, literacy was still the exception rather than the norm. Therefore, oral culture was still the more prevalent mode of personal interaction among most people. In particular, swearing an oath in the name of the Lord was of supreme consequence. Such an oath was most binding. By invoking the Lord’s name, Nephi is binding himself with the strongest of oaths. It and his subsequent arguments convince his brothers to accompany him on another attempt. Apparently, however, the brothers did not make a similar vow.
Redaction: Verses 15–20 are a discourse given by Nephi to his brothers. As with any sermon or speech that appears in the Book of Mormon, there is no way of knowing if it represented the actual words or simply the remembered/reconstructed words. Did Nephi keep a paper record or notes—a diary of sorts—that he later used in writing his small plates? There is no evidence one way or the other. However, these words, spoken by Nephi to his brothers, are written by Nephi and may accurately reflect Nephi’s memory of the occasion. As a literary technique, quoting this speech allows Nephi to make his moral point without having to describe it. It is a dramatic presentation to his brothers, and we may identify Nephi’s points as he meant his brothers to do.