In 1965 biblical scholar John Sawyer, who was not a Latter-day Saint, wrote “that the term mosiah was an ancient Hebrew term … a ‘word invariably implying a champion of justice in a situation of controversy, battle or oppression.’
“Apparently the form of the word Mosiah is a ‘hiphil participle’ in Hebrew. It occurs in the Hebrew in [several Old Testament texts] that in all probability were on the Plates of Brass. This word, however, was not transliterated into the English by the King James translators, and thus the Hebrew would not have been known to Joseph Smith … .
“Sawyer concludes that the term applied to a particular kind of person or role and was sometimes a title designating ‘a definite office or position’” (Welch, “What Was a ‘Mosiah’?” 105–6).