Samuel begins speaking by testifying that he is speaking by the revelation (v. 5). The first judgment of God that he mentions is “the sword of justice” that hangs over the Nephites. As an attribute of God, justice is what the people deserve. It is based upon the keeping of the law or the breaking of the law. In this case it was the law of Moses (v. 1 above). The sword depicts war or destruction, thus the Nephites were facing destruction. However, this destruction was not to come for four hundred years (v. 5). Would this cause much anxiety today if a prophet told you that your city and its inhabitants would be destroyed in four hundred years? Probably not. Alma had given Helaman, his son, the same prophecy nearly seventy years before (Alma 45:12–13) and it hadn’t had too much effect since that time.
Perhaps the four-hundred-year prophecy was just a reminder or an attention getter. It may have been an appeal to their pride as a people as well. Whatever the reason, the Lord did inspire Samuel to say it. He only warns the present inhabitants of their imminent danger after he warns them of the future destruction more thoroughly (Helaman 13:12–39).
Repentance as the condition for not being destroyed was based on the assured coming of Christ (v. 6). Since the time of his coming had been foretold for nearly six hundred years (1 Nephi 10:4; 19:8; 2 Nephi 25:19), and the time was almost there (about 6 B.C.), it was appropriate for the occasion.
The angel who declared it to Samuel (Helaman 13:7) may have been an earlier appearance than the voice of the Lord that had sent him again to the city. The angel’s appearance being earlier is implied by Samuel’s reference to his earlier rejection (v. 7). The continued warning also implies that the very generation to which Samuel is speaking will have the word of God and the Lord’s Spirit taken away if they do not repent (v. 8). Also, the four hundred year, fourth generation destruction will still take place (v. 9–10). The condition of repentance is held out to both generations, then and four hundred years later (v. 11).