Melissa and Taylor Halverson write that just three years before the coming of Christ to the American continent, secret combinations destroyed the stable Nephite government. Social chaos quickly followed as the society divided into numerous clans and tribes (3 Nephi 7). Only six years earlier the people had enjoyed great peace and prosperity because of their repentance and righteousness. But now, only darkness and the most dismal of times awaited them. Why would a blessed and prosperous people choose this destructive path?
Mormon, the great prophet/historian, insightfully explained the whole situation using symbolic terminology, "And thus six years had not passed away since the more part of the people had turned from their righteousness, like the dog to his vomit, or like the sow to her wallowing in the mire." (3 Nephi 7:8). This is not a pleasant scene to paint upon the mind, yet Mormon wastes no time describing the people's iniquity nor does he make apologies for so doing. Mormon's use of this symbolism most likely derives from ancient Israelite society. For example, in Israel a sow (hog) was an unclean animal. Anyone who ate a sow became defiled according to the Mosaic Law (Deuteronomy 14:8 (3-8)). Similarly, a dog was not looked upon with high regard, often verbally being used as an insult of the basest sort (1 Samuel 17:43, 2 Samuel 16:9). By comparison to unclean animals, Mormon is labeling the Nephite society as intrinsically unclean.
The Book of Mormon employs terms sometimes infrequently found in common speech, such as mire
and wallowing, therefore brief definitions are due. Mire is deep mud that thwarts one's progress, and wallowing is heavy or clumsy movement often associated with a sow rolling it's body in the mire. A sow naturally "wallows in the mire" after being washed clean, becoming just as dirty as if the cleansing had never taken place (2 Peter 2:22). These ideas evoke images of uncleanliness, filth, and repugnance. Not only has Mormon labeled the Nephite society as defiled (unclean), he also has made an observation about their natural tendency to turn to filthy things after having repented and being washed clean by the atonement.
Returning to the dog imagery, Mormon has placed one of his more powerful observations into a simple six-word phrase. Consider for a moment why a dog would ever have need to vomit in the first place. Vomiting is a natural biological defense system or process of protection that the body endures when we have consumed something harmful or disagreeable. The dog likely ate because he was hungry, but he chose poorly, consuming a harmful substance. Even after his body properly reacted to save him by ejecting the harmful substance, the dog's natural desires were not satisfied and he turned to something more revolting than his first meal: the harmful substance mixed with his vomit.
The Nephite society, turned to even grosser iniquities, mixed with the first, because their appetite for wickedness could never be satiated. Thus they fell headfirst into a dizzy downward spiral of self-destruction "like the dog to his vomit, or like the sow to her wallowing in the mire." With this deft phrase, Mormon captures in a parallelism the cyclical pattern of wickedness and apostasy that is repeated throughout Nephite history in the scriptures. [Melissa and Taylor Halverson, "A Repugnant Phrase in Scripture: The Dog to Its Vomit," in Meridian Magazine, LDSWorld, [http://www.ldsworld.com/site/display/0,3940,38327,00.html]]