After telling the Gentiles that they inherit the promise of the land, he reminds them that they inherit both the positive and negative aspects of the curse. They too will be blessed if they follow God, but cursed if they do not. Therefore, Mormon calls the Gentiles to repentance in verse 22.
Verse 23 echoes Isaiah 34:4. Verse 24 refers to Micah 5:8, but in the form quoted in 3 Nephi 20:16. The point of those two verses is to note that the Gentiles must also repent, lest they invoke the negative promise, and they too would be destroyed; “lest a remnant of the seed of Jacob shall go forth among [them] as a lion.” Ironically, Mormon prophecies that God’s instrument of their possible destruction would be the remnant of the seed of Jacob, a phrase referring to the seed of Lehi. In other words, the Lamanites would be that instrument.
This is not the end of a chapter in the 1830 edition of the Book of Mormon.