The Ammonihahites opened their comments with this objection, and repeat it here. They appear to be of the opinion that they are sufficiently important that the Lord should send them more than one messenger. Perhaps this is one of the reasons that the Lord had Amulek prepared to work with Alma, so that there would be a testimony of two people against these people, meeting some unstated assumption that they had. The Lord certainly knows the circumstances that we might require to believe, and will provide them. The Ammonihahites are given the full opportunity to repent before the destruction befalls them. When Alma is finished, Amulek will stand forth among them to provide the second witness against them.
Textual: The original Printer’s manuscript fairly consistently had the name Ammonidah. In all cases, this was corrected to Ammonihah before submitting the manuscript to the printer (see Book of Mormon Critical Text. FARMS 1987 Vol. 2, critical apparatus for chapter 9).
This is yet more indication that the text was dictated, and that mistakes in hearing the unfamiliar words made it into the manuscript. That these errors made it from the original to the Printer’s copy prior to correction suggests that Joseph Smith was not performing critical readings of the text until prior to submission.