This chapter talks about how people think that there should be no more scripture after the Bible. In verse 8:
Wherefore murmur ye, because that ye shall receive more of my word? Know ye not that the testimony of two nations is a witness unto you that I am God, that I remember one nation like unto another? Wherefore, I speak the same words unto one nation like unto another. And when the two nations shall run together the testimony of the two nations shall run together also.
A powerful example of this to me is how the Book of Mormon and Isaiah have so many similar passages. These are books that were written far apart in both time and distance, and yet the message is the same. God spoke the same words unto one nation like unto another.