The original manuscript is extant here and has the plural “your bodies” in the earlier clause but “your body” in the later clause. Meanwhile, this same passage twice uses the singular “that same spirit”. Amulek here is speaking to many people, which might explain the plural use of “your bodies”, but one wonders about the lack of consistency, especially since the otherwise identical phraseology “possess your body/bodies” is used each time. And if there is an error here, we wonder which reading is correct, the singular body or the plural bodies.
We have already discussed one case where there was an apparent mix-up between singular body and plural bodies:
In this case, the 1953 RLDS emendation to the plural bodies appears to be correct.
On the other hand, here in Alma 34:34 the plural usage “your bodies” with the singular “that same spirit” can be defended. Consider, for instance, the following example which mixes singular and plural in a similar way:
Quite clearly, the text here consistently refers to plural spirits, but just as clearly uses the singular “this mortal body” (which is undoubtedly intended since both this and body are singular). In the same way, the usage in Alma 34:34 is possible.
There is one other passage that switches from singular to plural, but in that instance the number is consistent within each clause of the passage:
This example suggests that as long as grammatical number is kept consistent within the same clause, we can have mixtures of singular and plural forms of spirit and body. In 2 Nephi 9:13, on the other hand, the occurrence of “the body of the righteous” is incorrect since the righteous refers to a plurality, as in the previous clause (“the spirits of the righteous”). In other words, in the earliest extant text for 2 Nephi 9:13 there is a mixture of singular body and plural righteous. So the emendation within the clause for 2 Nephi 9:13 should be followed, but mixtures across separate clauses (as in Alma 11:45, Alma 34:34, and Alma 40:11) can be kept.
Summary: Accept the mixture in grammatical number for spirit /spirits and body/bodies in Alma 11:45, Alma 34:34, and Alma 40:11; on the other hand, the emendation in 2 Nephi 9:13 of “the body of the righteous” to “the bodies of the righteous” should be maintained.