Cultural/Textual: Mormon has mentioned prisoners previously. This is the first time that he mentions women and children being taken as prisoners, and it is the first time that he mentions that they “did offer them up as sacrifices unto their idol gods.” In a Mesoamerican context, human sacrifice was an entrenched part of the culture, and was certainly practiced before this particular mention in Mormon. As discussed in the story of the Anti-Nephi-Lehies, the best explanation of the events of that story revolve around the need for sacrifices to accompany an enthronement of a new king (see the commentary following Alma 16:3-4).
If human sacrifice had been a part of Mesoamerican culture for hundreds of years, and captives from the Nephites had quite likely been sacrificed before this time, why mention it now? The key is that there is a shift in the rules of the game. The men would have understood that this was an aspect of warfare. However, this instance is not male captives, but women and children. It is this shift in the type of captives taken for sacrifice that enrages the Nephites, not just the sacrifice.
How may we be certain that it was the women and children being captured and not specifically sacrifice that was the notable aspect of this event? There is very little chance that the sacrifices would be performed on the field of battle. Captives were taken back to the cities for sacrifice. Therefore, the Nephites would not have seen the sacrifice. For Mormon to know that the women and children were headed for sacrificial altars requires his unstated cultural understanding that sacrifice was the reason for taking captives. Since they were captured, therefore they were to be sacrificed.
It is this type of information that tells us about the nature of the text that we have from Mormon. Mormon is writing in a high-context society. Malina and Rohrbaugh describe this type of society and writing for the Biblical writers:
“In this way biblical authors, like most authors writing in the high-context ancient Mediterranean world, presume that readers have a broad and concrete knowledge of their common social context. That is a given. Moreover, a document like John makes the additional assumption that its original readers/hearers were members of an alternate society. It expects them to have a high knowledge of that peculiar context and thus offers little by way of extended explanation.
…By contrast, “low-context” societies are those that assume “low” knowledge of the context of any communication. They produce highly specific and detailed documents that leave little for the reader to fill in or supply.” (Bruce J. Malina and Richard L. Rohrbaugh. Social-Science Commentary on the Gospel of John. Fortress Press, Minneapolis, 1998, pp. 16-7).
The example at hand demonstrates how this high-context expectation works. Mormon has never mentioned human sacrifice before, even though stories like the Anti-Nephi-Lehies are strongly suggestive that the practice was known in the Book of Mormon times. We have no mention, even though archaeology also suggests that it would be present in those times. It is never mentioned, precisely because it is part of the high-context cultural information that Mormon assumes should be part of the background his reader brings to the text.
When we do get a mention of the sacrifice, it is not because Mormon is explaining that human sacrifices occur, but because they have taken women and children for those sacrifices. This is the “new” piece of information that would have been significant in the high-context society. The rules had changed, and that change was worthy of special note. This instance substantiates the assumption that Mormon is living in a high-context ancient culture, and that what he writes requires that we understand that background to fill in the details. Details he explicitly mentioned come from the contrast to expectations, but provide for us some of the most valuable clues to rectify our cultural vision to that of Mormon.