The division of the family is no orderly, polite separation like the negotiated and courteous parting of Abraham and Lot (Gen. 13:8–12). When Nephi’s brothers decide on murder, Yahweh warns him to gather those of a similar heart and flee. Laman and Lemuel had tried to kill Nephi before, and he had not fled (1 Ne. 17:48). Now the situation has changed, Yahweh specifically commands him to leave, and Nephi immediately obeys.
Nephi received no angelic protection. The Spirit had prevented Laman and Lemuel from harming Nephi in the past (1 Ne. 17:48), but now divine intervention consisted of the warning to go. This instance allowed the disintegration of Lehi’s family, where such interventions before had preserved it.
History: Verse 6 defines the original group of “Nephites.” Nephi’s party consists of himself, Sam, Jacob, Joseph, his sisters, Zoram, and their families. Sorenson estimates that perhaps eleven adults and thirteen children were in the group. This left Laman, Lemuel, possibly Ishmael’s sons, and their families as the “Lamanites.” Thus, Nephi may have taken more than half of the Old World party. One of the most important phrases is “all those who would go with me” at the end for verse 5. Nephi accounts by name for nearly every person known to be in the party from the Old World, yet he also list “all those who would go with me.” I hypothesize that these “others” are New World peoples who joined with the Nephites. (See 2 Nephi, Part 1: Context Chapter 1, “Historical Setting of 2 Nephi.”)
How, then, do the Lamanites later become more numerous than the Nephites? Jarom 1:6 claims that by around 390 B.C. the Lamanites “were exceedingly more numerous than. . . the Nephites.” The most logical answer is that both the Nephites and the Lamanites intermingled with the natives of the area and that the generic labels included more than just those with genetic relationships to the Old World immigrants. (See2 Nephi, Part 1: Context, Chapter 1: “Historical Setting of 2 Nephi.”)