Nathan Arp has suggested (personal communication, 18 January 2006) that the occurrence in this verse of the indefinite article a before Moses is an error. It is possible that during the early transmission of the text an intrusive a was added before Moses, perhaps under the influence of the a in the following clause: “and I will give power unto him in a rod”. Another possibility is that previous references in this chapter to “a seer” and “a choice seer” (see verses 6, 7, and 11) led the scribe to accidentally write a Moses. In the Book of Mormon proper names are not otherwise used generically (as in “he’s an Einstein” or “she was another Shakespeare”, as we might say in modern English).
Here in verse 17, the text is specifically referring to Moses the prophet; Moses is not being used as a generic noun. Note that the preceding text has already referred to Moses, so there is no need for a Moses:
Note especially that a Moses does not occur in verse 10 (that is, as “and a Moses will I raise up”), even though that phrase says the same thing as “I will raise up (a) Moses” here in verse 17:
But after verse 17, the text refers to the other seer that the Lord will raise up:
(This last passage has been emended in the second line to read “I will raise up one”; see the discussion under 2 Nephi 3:18 in part 1.) The phraseology a Moses could be used to refer to this other seer, but in verse 17 the text is still referring to Moses proper.
There is one case in 𝓟 where Oliver Cowdery accidentally added the indefinite article, namely, before God in the book of Alma:
In this passage, Oliver Cowdery initially wrote God as gd in 𝓞; the lowercase g was in error, plus the o vowel was missing. So Oliver erased the gd and then wrote the correct God inline. But when he came to copying the text from 𝓞 into 𝓟 (some six months later), Oliver misread his erased gd as the indefinite article a. Consequently, 𝓟 and most of the early editions (1830, 1837, 1841, and 1849) had the incorrect reading a God. The 1840 edition (and the 1852 LDS edition) removed the intrusive a here. So a can intrude, although there are no instances where a was added before a personal name except possibly here in 2 Nephi 3:17.
The critical text will accept the emendation Moses here since it works so much better, although there is not much evidence for the accidental insertion of a before names in the history of the Book of Mormon text.
Summary: Emend 2 Nephi 3:17 to read Moses rather than a Moses; Moses has already been identified by name, and the text here is referring to Moses himself, not to someone else that could be considered another Moses.