The statement that his father lived in a tent (1 Ne. 2:15) marked a shift in Nephi’s story. From this point on, it is the story of Nephi much more than the story of his father or family. This is highlighted by beginning the story with Nephi’s own experience with Yahweh. Nephi had prayed to learn of the truth of his father’s prophetic mission. Now he receives his own.
First, Yahweh declares that Nephi is blessed because of his father. That is an essential beginning for what will become the Nephite people. Yahweh’s blessing is upon them from the beginning. Next, Nephi receives the promise that there is a promised land. More importantly, he is told that it is “a land I [Yahweh] have prepared for you.” The entire family is going to this land of promise, but it was prepared for Nephi, and presumably his descendants. Lehi received that same blessing of a land of promise, but Nephi doesn’t have Lehi speak of the land of promise until Second Nephi Chapter 1, though he does suggest that his father knows that they are going to a land of promise in 1 Nephi 7. All of the references to the land of promise in 1 Nephi (there are seven of them) come when Nephi is directly speaking, or narrating.
Verse 20 presents the essential Nephite promise. They will prosper if they keep the commandments. The Israelites had been led to a promised land which they believed had been granted them in perpetuity. Yahweh made no such promise to Nephi. A choice land was prepared for them, but it was theirs only on conditions of faithfulness to God’s commandments. Much of the Book of Mormon demonstrates both the affirmative and negative versions of that promise. The Nephites do prosper when they are righteous. When they are not, they are subject to different types of destruction—until their disobedience finally culminates in their total destruction.