Interestingly, Ammon either had with him a copy of King Benjamin’s speech or he knew it by memory, for he "rehearsed unto [the people of Limhi] the last words which king Benjamin had taught them, and explained them." Ammon and King Limhi most likely believed that this people would benefit by knowing the revelations that Benjamin had given his people, and also by following Benjamin’s public laws, since these statutes and ordinances had already proven to be very beneficial to all the people of Zarahemla.
For example, King Benjamin, in his accounting of how he had discharged his duties, declared that he had not allowed the people to "murder, or plunder, or steal, or commit adultery… or any manner of wickedness" (Mosiah 2:13). These are sometimes referred to as Benjamin’s "rules of public order." This list of five public laws is found six other times in the Book of Mormon. In three instances, the list functions as a measure of how well the kings and rulers had maintained public order (see Alma 23:3; Alma 30:10; and Mosiah 29:14–15, 36). In Helaman 6:23; Helaman 7:21; and Ether 8:16, they serve to indicate how wicked and corrupt that particular society was. Limhi would likewise have been eager to know that he had discharged his royal duties by leading his people in wisdom, truth, and righteousness. More is said about Limhi’s people entering into a covenant with God in Mosiah 21:31–35.
John W. Welch, "Benjamin the Man: His Place in Nephite History," in King Benjamin’s Speech: "That Ye May Learn Wisdom," ed. John W. Welch and Stephen D. Ricks (Provo, UT: FARMS 1998), chapter 2.