Reference: Nephi follows Isaiah 29:10: “For the Lord hath poured out upon you the spirit of deep sleep, and hath closed your eyes: the prophets and your rulers, the seers hath he covered.” Nephi is neatly applying the metaphor of sleep to the apostate world’s lack of understanding. He has described the world as dreaming a “dream of a night vision” and now likens its state to that of a sleeper with closed eyes. He then applies the eyes closed in sleep as eyes closed against understanding. At this point, he reprises Isaiah 6:9–10: “And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not. Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed.”
Nephi characterizes the modern Christian apostate world by its unseeing eyes. They profess Christianity but lack a true understanding of Yahweh’s gospel. In this state, they need the words of Nephi’s people to restore them to that complete knowledge.
To emphasize the world’s apostasy, Nephi also alters the last phrases of this verse. In Isaiah, the prophets and seers are “covered” because they have apostatized. In Nephi, the prophets and seers are “covered” because the people have apostatized and rejected them.
The image of sleep is necessary as Nephi expands Isaiah’s prophecy. Nephi relies upon Isaiah, not as a proof text but as a support for his own prophetic message.