Moroni knew where the prisoners were and decided to take them without
an exchange. To do so, he creates a ruse that will make the process easier.
What he requires is to “find a man who was a descendant of Laman.” He finds one
who was one of the guards who had to flee when Amalickiah’s men killed the
Lamanite king. The simplest reading of this ruse would be that Moroni was
looking for someone who looked like a Lamanite and who had a dark skin.
The actual event proves the opposite. There was no visible difference
between the Lamanite and the Nephites who went with him. If there were one
dark-skinned man accompanied by several visibly “white” men, the ruse couldn’t
have worked. It is therefore much more reasonable that what was needed was
someone to speak in a language and perhaps an accent that would be convincing.
Indeed, it was only the man named Laman who is depicted as speaking. (Brant A.
Gardner, Book
of Mormon Minute: A Scripture Commentary,
volume 3)
Further Reading:
Brant
A. Gardner on Alma 55:4-8 (transcription taken from Second Witness:
Analytical and Contextual Commentary on the Book of Mormon)