To all of those to whom, in previous verses, Nephi had reported that they will believe that they need no more of God’s word, Nephi promises that God will continue to give to the children of men line upon line, precept upon precept. Nephi is quoting from Isaiah 28:10. This was not a verse that he had quoted before now, so it is a reference that he expects his audience to understand.
Verse 30 also begins a narrative shift. Where Nephi had been speaking in his own voice up to this point, verse 30 declares “thus saith the Lord God.” I will be God’s words reprising what Nephi has already said.
The result of the coming forth of the Book of Mormon will be that there will be a restitution of the wisdom of God, and a reversal for those who denied the truths of the Book of Mormon. The end times will be when things are made right. For Isaiah, it was a military victory. For Nephi, it was a spiritual victory. In both cases, the Lord declares that he will be merciful to the truly repentant.
The idea that the Lord’s hand is lengthened out all the day long is an allusion to the oft-repeated phrase in Isaiah that Jehovah’s arm is stretched out still.
Although this ends our chapter 28, it was not the end of a chapter in the 1830 edition. The original chapter includes our chapters 28, 29, and 30. The shift to Jehovah as the speaker will continue at the beginning of chapter 29.