The formal section of blessings begins in this passage. This is the only record of a blessing we have for Laman, Lemuel, and the sons of Ishmael. Sam will receive a blessing along with his posterity in 2 Nephi 4:11. They are all to be given a “first blessing.” There is no internal definition of what Lehi means by a “first blessing.” It does not appear to be a first of many, but perhaps a “first” as in “principal.”
This set of men receives a blessing together because they are older than Nephi but are being asked to reverse the normal social order and submit to Nephi as their ruler. If they do so, they will receive the “first blessing.” If not, it will be added to Nephi. Nephi does not describe this blessing, nor does he write any blessing that he received. He does not explain why he leaves out the details of these blessings. It is most likely that Nephi was given a specific blessing, but he elected not to enter it, instead choosing to record Lehi’s declaration that he should be the legitimate ruler. As part of the charter of his people (the plausible purpose behind his selection of material of the book of 2 Nephi; see2 Nephi, Part 1: Context,Chapter 2, “Overview of 2 Nephi”), it is this authority that matters more than the blessing itself.
Lehi has considered these men a set whom he compares to Nephi. As older men in the family, these are they who must give up personal pride to accept Nephi as their leader. Jacob and Joseph are younger than Nephi and therefore have no claim upon the right of rulership. Therefore, they receive blessings of their own in chapters 2 and 3, not the collective blessing of the older sons.
Lehi certainly perceived that Laman, Lemuel, and the sons of Ishmael would not honor Nephi’s leadership. Perhaps for this reason there is no specific blessing for them. However, Nephi makes sure that we understand that Lehi did not leave their lineages without a blessing, even if the men themselves had none. Thus, we have in chapter 4 a blessing upon the children of those whose conditional first blessing eventually went to Nephi. Sam provides an interesting contrast. He receives a personal blessing but does so along with his children, as though he too had been “skipped” in the rightful order of blessings.