3 Ne 7:1 they...did murder the chief judge of the land
"In A.D. 30, the last chief judge of the once-great Nephite nation was assassinated by a secret combination of judges, lawyers, and apostate high priests. That murder ended the sole republic of the Nephite record and continued a process of social disintegration halted only by the coming of the resurrected Christ. In that process, the unrighteous Nephites destroyed what remained of governmental regulation and divided their society into tribal units. One large band selected 'one of the chiefest who had given his voice against the prophets who testified of Jesus' to be their king. (3 Ne. 7:10.) The reign of the judges had lasted only 120 years." (James R. Moss, Ensign, Sept. 1977, 61)
3 Ne 7:2-4 they did separate one from another into tribes
Anthropology teaches that different societies develop different methods of government based on their degree of sociological development. Accordingly, the family unit is the most basic form of government, tribal government is next, followed by city-states, nations and empires. Just before the Savior comes, the Nephites take a big step backward. Their government collapses and they revert to one of the most basic forms of government, and thus they became tribes and leaders of tribes. The least civilized and least enlightened societies in the history of mankind have almost always been governed by a tribal system.
3 Ne 7:2-6 they did destroy the government of the land
The biggest mistake that a parasite can make is to destroy its host. The wicked secret combinations had proved the destruction of the government and thereby destroyed their main source of strength and authority. The Gadianton robbers much preferred to control the Nephite government from within rather than have to separate from the Nephites and fight them as opposing armies. But the regulations of the government were destroyed and with it went the authority of the combining judges. The lesson to us is to be careful not to let modern secret combinations destroy the government.
Joseph Fielding Smith
"Now I tell you it is time the people of the United States were waking up with the understanding that if they don't save the Constitution from the dangers that threaten it, we will have a change of government." (Conference Report, Apr. 1950, p. 159 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 402)
Joseph Smith
"Even this nation will be on the very verge of crumbling to pieces and tumbling to the ground, and when the Constitution is upon the brink of ruin, thus people will be the staff upon which the nation shall lean, and they shall bear the Constitution away from the very verge of destruction." (quoted in Journal of Discourses 7:15 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 403)
3 Ne 7:8 in six years...the people had turned from their righteousness, like the dog to his vomit
Peter spoke of a proverb in which, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire (2 Pet 2:22, see also Prov 26:11). Of note, our version of Proverbs is slightly different but Mormon quotes the same passage as Peter-which was apparently available to him in the brass plates of Laban.
The Nephites had stooped so low that similes of vomit eating dogs and wallowing swine seemed to be the most appropriate representations, especially since both could go from clean to dirty in such a short amount of time. Less than ten years prior, there was not a living soul among all the people of the Nephites who did doubt in the least the words of all the holy prophets (3 Ne 5:1). Now there were but few righteous men among them (v. 7). Elsewhere, Mormon laments:
'...how quick to do iniquity, and how slow to do good, are the children of men; yea, how quick to hearken unto the words of the evil one, and to set their hearts upon the vain things of the world!
Yea, how quick to be lifted up in pride; yea, how quick to boast, and do all manner of that which is iniquity' (Hel 12:4-5).
3 Ne 7:15 Nephi was visited by angels and also the voice of the Lord
"There are some Book of Mormon figures whom we glimpse only briefly, whom we can never know well, but who intrigue us immensely because that brief glimpse seems to show us the tip of a remarkable iceberg. Nephi, the grandson of Helaman, is such a figure for me. He moves very quietly onto the scene and backs very quietly out of it, but he is no ordinary record-keeper. This is the man who was the spiritual leader of the Nephites at the time of the birth of the Savior and during the Savior's ministry on the American continent. This is the man who wrote the account that Mormon abridged as Third Nephi, one of the most powerful sections of the Book of Mormon. So great was his faith and so vigorous his spiritual power that he raised his brother from the dead and communed regularly with angels.
"Rereading Third Nephi, I have become more and more aware that perhaps our only real access to Nephi's character is through Mormon's perception of him as Mormon reads and abridges Nephi's record. I think Mormon must have been impressed with Nephi because he keeps interrupting his narrative to pay respect, either directly or indirectly, to the earlier prophet. (See, for example, 3 Ne. 7:15-16 and 3 Ne. 8:1.) Since we can, in effect, know Nephi only secondhand, it seems important that we try to look through Mormon's eyes, try to see Nephi as Mormon saw him. Careful study of Mormon's abridgement confirms in both subtle and obvious ways that Mormon knew he had encountered a remarkable human being.
"I have often wondered, in reading between the lines, if Mormon might have been a little reluctant to cut and summarize Nephi's account. It appears that at times he prefers to omit parts of the account rather than attempt to shorten it. Speaking of Nephi's ministerings, for instance, he says, 'And all of them cannot be written, and a part of them would not suffice, therefore they are not written in this book. And Nephi did minister with power and with great authority.' (3 Ne. 7:17.)
"Even in making rather casual references to the record, Mormon adds extra praise for Nephi: 'And now it came to pass that according to our record, and we know our record to be true, for behold, it was a just man who did keep the record-for he truly did many miracles in the name of Jesus; and there was not any man who could do a miracle in the name of Jesus save he were cleansed every whit from his iniquity.' (3 Ne. 8:1.)
"...Interesting as these kinds of observations are, it is nevertheless Mormon's perception of Nephi's great spiritual stature that really stirs our minds and hearts. More concerned about the well-being of his people than about himself, strong in spirit and will, Nephi kept a record chiefly to bear witness to the divine ministry of Jesus among the Nephites. Moving chronologically through Third Nephi, we become more and more aware of Nephi's spiritual magnitude, largely, I think, because Mormon was keenly aware of that magnitude. It is somewhat difficult to get even a limited understanding of Nephi's character because there is so little direct description of him and there are so few explicit references to his activities. I find, however, that as I read Mormon's account, a picture of a dynamic spiritual leader takes shape because the few statements Mormon does make resound through my mind as I read the book of Third Nephi." (Marilyn Arnold, "The Nephi We Tend to Forget," Ensign, Jan. 1978, 69)
3 Ne 7:19 in the name of Jesus did he cast out devils...and even his brother did he raise from the dead
Some of the wicked of Nephi's time were quite concerned with fairness. They asked, if...he be the Son of God...will he not show himself in this land as well as in the land of Jerusalem? (Helaman 16:18-19) Unwittingly, they were complaining because they did not know that they were to receive the same privilege as the Old World Jews. Indeed, they were to receive the personal ministration of the resurrected Lord. According to the spirit of fairness, these wicked, in their ignorance, may have wondered how it was that Christ was to perform so many mighty miracles among the Jews but not among them. Again, they did receive witness of the same kind of miracles, both by the Savior himself and by Nephi.
As a type for the Lord, the prophet Nephi went about performing incredible miracles. Nephi cast out devils as Jesus did, he cast out unclean spirits as Jesus did, and he even raised the dead as Jesus did. Nephi's words demonstrated that he had greater power than they, for it was not possible that they could disbelieve his words (v. 18). This perfectly parallels the powerful teachings of the Savior, the people were astonished at his doctrine: For he taught them as one having authority, and not as the scribes (Matt 7:28-9). The parallel is also chronological for these ministries were occurring at the very same time. So we see that the Lord also has a sense of fairness. He gave witnesses to both nations so that when those witnesses were summarily rejected, He would be justified in destroying them-in the New World, at the death of Christ, and in the Old World, at the hands of the Romans, A.D. 70.