These verses begin a new chapter in the 1830 edition, and they mark a change in the nature of the text. To this point, Mormon has been working with the abbreviated text of Nephi (3 Nephi 5:10). In verse 7 Mormon notes that his current account is abbreviated and leaves out many of the words of the Savior. He notes that much of this information was available, but that it was contained on official plates of Nephi.
At this late point in his text, Mormon tells us the reason he is writing. According to verse 8, he has written the part of the Savior’s message that he wrote “to the intent that the may be brought again until this people, from the Gentiles.” It is safe to assume that not only this particular section, but his entire work is written to that end. He specifically mentions it in this context because that time period, and particularly the relationship of this message and the Gentiles has been the subject of the parts of the Savior’s discourses that have been added.
This further substantiates the idea presented in the analysis following Words of Mormon 1:1 that Mormon’s original introduction to his work was lost with the 116 manuscript pages, and that function of introduction was not replaced with the small plate material was translated.