As Nephi is writing this introduction to the New World creation of the Nephite people, he began by establishing that the conflict with Laman and Lemuel survived the journey across the ocean. One of the elements of the Old World stories of ethnogenesis, or the stories of the beginnings of a people or nation, is that they have an ancestral enemy. Nephi uses Laman and Lemuel in that function.
At this point, Nephi creates a new beginning. He notes that Jacob is the firstborn in the wilderness. While that was certainly true, it is perhaps mentioned to emphasize that Lehi is now dealing with a slightly different set of his sons. To this point, the blessings have been relatively short, but for Jacob and Joseph they will not only be extensive, but provide great doctrinal expositions.
The enmity with Laman and Lemuel came across the ocean, but so did the gospel. As Lehi begins the blessing, Jacob is firmly associated with Nephi and with Jehovah. Given the focus of Lehi’s preaching in Jerusalem, and all that we will see of Nephi in his two books, it is significant that Lehi specifically mentions that “I know that thou art redeemed, because of the righteousness of the Redeemer.” The Messiah as redeemer is Lehi’s message, and it is Nephi’s message. The knowledge of the redeeming Messiah, that Nephi believed to have been lost in the Old World, is thus firmly established during the foundation of his people in the New World.