This chapter also ends the longer chapter in the 1830 edition. The reason for the ending is not that Nephi is through with his discussion, but rather that the quotation from Isaiah is finished. When we finish these three verses, we reach the end of Isaiah, Chapter 29. That triggered the chapter ending.
Isaiah had been describing the reversal of fortune that the words of the book will bring. These verses continue to show the power of the Lord as manifest through that marvelous work. Even though there will be times when the children of Israel will be beaten low, yet will the Lord be exalted. For Jehovah, it is also a reversal, “he shall not now be ashamed.”
The result of the marvelous work and a wonder, the result of the words of the book—which in Nephi is clearly the Book of Mormon—will bring all to understanding. Even those who before erred, or before murmured, will learn true doctrine through the Book of Mormon.