Jerald Simon notes that when Nephi really wanted to "persuade [his brethren] to believe in the Lord their Redeemer," (1 Nephi 19:22-23), and to awaken them to the knowledge of who they were and how they fit into the larger picture of the plan, he turned to Isaiah's rich messianic messages and assurances that God's promises to his covenant people would be fulfilled in the latter days. Nephi not only wanted his brethren to see the Savior and come unto Christ, but he wanted them to remember that they were part of the foreseen scattering and gathering of the house of Israel, that they were being led by a prophet of God.
Although Nephi clearly understood the futuristic implications of Isaiah 48 and 49, his selection of these Isaiah chapters was most appropriate if Laman and Lemuel were to be persuaded to follow his counsel to "hear ye the words of the prophet" and "liken them unto yourselves." Nephi not only wanted Laman and Lemuel to hear the words of the prophet Isaiah but also two other prophets, his father Lehi and himself.
It is clear that Nephi's charge to "liken" the words of Isaiah was uttered sometime after arriving in the promised land and before the death of Lehi. A closer scrutiny of the passages at the conclusion of 1 Nephi and the beginning of 2 Nephi indicate that these events, although found in two separate books, took place at one time. In other words, 1 Nephi 19 through 2 Nephi 4:12 all happened simultaneously, culminating with the death of Lehi. [Jerald F. Simon, "Researching Isaiah Passages in the Book of Mormon," in Covenants Prophecies and Hymns of the Old Testament, pp. 212-215]
Through the Wilderness to the Promised Land
(1 Nephi )