Rhetoric: It is tempting to look at verse 9 as a simple prohibition against racial prejudice. While such a prohibition is absolutely a correct principle, it is not the highlight of Jacob’s argument. Jacob is using structural opposites to make his case. Jacob creates a condition where degrees of righteousness move through generations and are altered in the journey.
Jacob sets up the contrast by warning the Nephites not to revile Lamanites “because of the darkness of their skins.” This historical cursing occurred in an earlier generation. Because of the collectivist nature of Nephite society, his listeners would assume that such a cursing would continue through generations; but Jacob checks such thinking. Rather, he identifies a positive trend in Lamanite traditions. Their obedience to Lehi’s commandment of monogamy and marital fidelity becomes a rhetorical lever in Jacob’s hands to emphasize the righteousness of that choice. The older generation may have been cursed, but the younger generation is manifesting increased righteousness.
In verse 10 Jacob presents the terrible parallel. The Lamanite fathers were cursed, but their descendants are no longer. Rather, the current Nephite generation, by their disobedience, is bringing a curse upon their own children. The Lamanites may have started wrong, but now they are doing right. The Nephites started right, but are now doing wrong. Those trends will make the Lamanites righteous and the Nephites wicked, a complete reversal of the world as the Nephites assume it to be.