We looked at verse 4 in the last episode for verses 2-4, but that episode was concerned only with the first phrase where Lehi is afraid for Laman and Lemuel. Verse 4 is repeated here because it is in the second phrase that the dream begins.
The dream begins in a dark and dreary wilderness. When a man dressed in white appears and is a guide, Lehi follows him, through a dark and dreary waste. Why is Lehi, the prophet, spending so much time in the darkness? Nephi doesn’t explain this darkness. When he has his own vision, it begins with the tree, not the darkness.
The answer is found in future texts. Two things are important. The first is that when Lehi ends speaking of the dream, he will prophecy, and most of his prophecy concerns the atoning mission of the Messiah (1 Nephi 10:4–10). The next comes in the great sermon Lehi gives in the New World, which is recorded in 2 Nephi 2. Importantly, he says:
"For it must needs be, that there is an opposition in all things. If not so, my firstborn in the wilderness, righteousness could not be brought to pass, neither wickedness, neither holiness nor misery, neither good nor bad. Wherefore, all things must needs be a compound in one; wherefore, if it should be one body it must needs remain as dead, having no life neither death, nor corruption nor incorruption, happiness nor misery, neither sense nor insensibility. Wherefore, it must needs have been created for a thing of naught; wherefore there would have been no purpose in the end of its creation. Wherefore, this thing must needs destroy the wisdom of God and his eternal purposes, and also the power, and the mercy, and the justice of God." (2 Nephi 2:11–12)
This is the meaning of the darkness. It is the necessary darkness of a world without an atoning Messiah.