In contrast to verse 1 where Mosiah simply “sends out” to discover the people, this verse emphasizes that he wrote his second message. While there were clearly literate Nephites, their percentage is less clear. If the messengers were reading the text to illiterate listeners, Mosiah thus ensures its accurate transmission. This particular message was so important to the people that Mosiah wanted it delivered precisely.
It also seems significant that he did not assemble the people but rather sent messengers among them. Those who lived out the ceremonial city-center were probably clustered in kinship groups. The message would be read to these kin groups.
Why is this important? First, the sheer size of the population may have made an assembly problematic, even though Benjamin had done so and Mosiah had likewise called an assembly when Limhi’s and Alma1’s people arrived. The second reason, I hypothesize, is that Mosiah was consciously keeping the groups small in informing them of his proposed action out of fear that the already tense divisiveness in Zarahemla might be exacerbated by certain kin groups attempting to create a coalition to install their own king and government. Such a real possibility will arise with the kingmen described in the book of Alma (Alma 51:4–5).