These eight verses describe thirty-eight years, from two hundred years to two hundred thirty-eight years after Lehi left Jerusalem (399–361 B.C.) (vv. 5, 13). The contrast between the Nephites and the Lamanites is very similar to what was described by Jarom’s father (see Enos 1:19–24).
The Lord’s promise, “Inasmuch as ye will keep my commandments ye shall prosper in the land,” was fulfilled among the Nephites (Jarom 1:9), but it was not without effort. Although the Nephites prospered (v. 8), it was the political and priesthood leaders who kept the prosperity going (vv. 7, 11–12). The formula that maintained their prosperous conditions was keeping the sabbath day holy, keeping the law of Moses for the intended purpose, looking forward to and believing in the Messiah to come, refraining from profanity and blasphemy, and having very strict laws of the land (vv. 5, 11). Our society should collectively learn and observe the same formula. The Nephites were warned conditionally of being destroyed from off the face of the land (vv. 10, 12). Our society is warned to defend the constitutional laws of the land to maintain our freedom
6 Therefore, I, the Lord, justify you, and your brethren of my church, in befriending that law which is the constitutional law of the land;
7 And as pertaining to law of man, whatsoever is more or less than this, cometh of evil.
8 I, the Lord God, make you free, therefore ye are free indeed; and the law also maketh you free. [D&C 98:6–8]
The description of their prosperity including machinery (v. 8) may raise some question. Machinery is something that has moving parts. What were these machines? How were they powered or operated? We will probably have to wait for the larger records of Nephi for our answers (Jarom 1:14). These answers will be restored after our faith in the present text of the Book of Mormon is tested (see 3 Nephi 26:8–11).
The weapons of war mentioned by Jarom and Enos suggest that the machinery was not too far advanced (Jarom 1:8 and Enos 1:20). However, an open mind as to the possibilities of what the Nephites had developed should be kept.