The remnant of the children of Amulon followed the traditions of their wicked fathers, putting all who believed the words of Alma and his brethren to death (v. 7). They did not know they were fulfilling a prophecy. As Isaiah said: “The grass withereth, the flower fadeth, but the word of our God shall stand for ever” (Isaiah 40:8); see also 1 Peter 1:24–25). The word of God comes through his servants. The Lord said to the Prophet Joseph Smith: “What I the Lord have spoken, I have spoken, and I excuse not myself; and though the heavens and the earth pass away, my word shall not pass away, but shall all be fulfilled, whether by mine own voice or by the voice of my servants, it is the same (D&C 1:38). Through his servant Abinadi, the Lord had said:
15 Behold, even as ye have done unto me, so shall it come to pass that thy seed shall cause that many shall suffer the pains that I do suffer, even the pains of death by fire; and this because they believe in the salvation of the Lord their God.
18 And in that day ye shall be hunted, and ye shall be taken by the hand of your enemies, and then ye shall suffer, as I suffer, the pains of death by fire. [Mosiah 17:14–18]
Mormon is paraphrasing and verifying the words of Abinadi in these verses (Alma 25:8–12). Although many years had passed and a new generation born and raised, the prophecy was fulfilled just as the Lord had said it would be.