The text in 2 Nephi 4:16–35 is often called the Psalm of Nephi. It is among the most eloquent, sublime writings found anywhere in scripture.
What circumstances is it written in response to? Lehi has just died, and Nephi feels strongly motivated to admonish his brothers. But he doesn’t have the strength of his father who has held this group together, and now Nephi finds himself completely alone. He tries to admonish his brothers, and it doesn’t work. He laments. He feels that he is weak and has failed. By the end, however, he is back on track and he knows in whom he trusts.
We can tell that his confidence has been rebuilt and restored. On the Small Plates of Nephi, there would have been no chapter break after the end of verse 35 where he concludes, "Behold, my voice shall forever ascend up unto thee, my rock and mine everlasting God. Amen." The text would have gone straight into the opening of 2 Nephi 5: "Behold, it came to pass that I, Nephi, did cry much unto the Lord my God, because of the anger of my brethren."
With that reinforcement, Nephi has renewed his commitment, and he has renewed his strength of spirit. Whatever self-reservations he had felt before, he now thinks, "I’m going to try again. I know that I’ve failed once already, but maybe God can soften their hearts." However, what happens? "But behold, their anger did increase against me, insomuch that they did seek to take away my life" (v. 2). They murmured and God warned Nephi in 2 Nephi 5:5 to leave. That was the setting and the subsequent development in which this psalm was written.
Book of Mormon Central, "Is ‘Nephi’s Psalm’ Really a Psalm? (2 Nephi 4:16–17)," KnoWhy 30 (February 10, 2016).