While there’s no way to tell, I like to read the beginning of Chapter 3 as if this is the first time Lehi and Nephi have seen each other since Nephi’s heart was softened in 1 Nephi 2:16. I think it makes more sense of Lehi’s relief in verse 8.
What in chapter 3 helps explain the Abrahamic Covenant or prepares us to read Isaiah better? Not sure, but I do wonder about these brass plates that Laban protects. They apparently have all sorts of prophecies of a branch of Israel, through Joseph’s line, being led away and brought back at some future point. I wish I knew all the reasons Laban was so upset with Laman. Were the plates valuable? Did the “elders of the Jews” that Laban associated with want the prophecies on the plates to be left unknown? Were there political dangers if those prophecies were interpreted certain ways and so they decided to keep them obscure? Were the plates a symbol of power in the city? In other words: why would Laban think that Laman wanted them? Wouldn’t this seem an absurd request? Or are there reasons someone would seek the records?
A second thought, though again not very related to Isaiah: I wonder if Laman and Lemuel go along with the idea to gather up all their gold, silver, etc., because they assume that Laban won’t trade and then they’ll get to take all their stuff in to the wilderness with them. 🙂 Either way, I think it’s clear that Laman and Lemuel are so angry (verse 28) because they were almost killed and all of their property was gone. Even if their father changed his mind and came back to Jerusalem, all of their property was now stolen and in the hands of Laban.