According to Richard Rust, Mormon used the principle of repetition in order to give the narrative focus and reinforce teachings. For example, the missionary endeavor of the sons of Mosiah, found in a single chapter in the 1830 edition of the Book of Mormon (Alma 17 through 20 in the current edition), is one of the most interesting stories in the Book of Mormon. By looking at this narrative as a single story, one discovers that its center is the kingdom of God in contrast with the kingdom of man, the power of God in contrast with that of man. It shows the ideal power of the missionary. Mormon's headnote underlines this theme: The sons of Mosiah reject their "rights to the kingdom" (an earthly kingdom with its accompanying power) "for the word of God" and go up to the land of Nephi "to preach to the Lamanites." There they experience "sufferings and deliverance." This acceptance of God's power and denial of earthly glory is emphasized in the first paragraph of the 1830 edition. The sons of Mosiah, we are told, "taught with power and authority, even as with the power and authority of God, . . . having refused the kingdom which their father was desirous to confer upon them" (cf. Alma 17:3, 6). From this point on, the word power becomes a repeated drum beat throughout the narrative.
The story that follows gains dramatic intensity by a greater movement into dialogue and monologue, with the emphatic word being power. (See Alma 17:29, 36; 18:3, 13, 20-22, 33-35; 19:17, 24.) By foregoing earthly power, Ammon shows forth God's power and thus opens up the most significant missionary harvest in the Book of Mormon. The editor's (Mormon's) heavily repeated use of the word translated as power drives home that point. [Richard D. Rust, "Recurrence in Book of Mormon Narratives," in Journal of Book of Mormon Studies, Vol. 3, Num. 1 (Spring 1994), pp. 47-50]