The Lord’s army consists of his “sanctified ones” and his “mighty ones.” These are the righteous who follow the Lord. this powerful army is turned against the unrighteous, for the Lord’s anger is now turned outward. With the recovery of the remnant of Israel, only a righteous Israel remains. Though the Lord had shown is anger towards Israel in the past, that anger was for the unrighteous, and now the righteous remnant has no reason to fear the Lord in his vengeful wrath.
Variant: The KJV Isaiah text reads “for mine anger, even them that rejoice in my highness.” The Book of Mormon translation removes the “even” and renders the phrase “for mine anger is not upon them that rejoice in my highness.” John Tvedtnes notes: “at first glance, it appears as though Joseph Smith mistook the KJV ”for“ to be the English conjunctive ”for“ (Heb. ky) rather than the dative ”for“ (Heb. l-), which would not be possible in Hebrew.” (Tvedtnes 1981, p. 52). If we were to read the Isaiah text as the Masoretic Hebrew text suggests, we might have "I have commanded my sanctified ones, I have called my mighty ones as agents of mine anger, even (upon) them that rejoice in my highness.
Tvedtnes argues for a different possibility, but this one should receive its due intention. If Joseph Smith were to be basing his text on the KJV itself rather than translating from the original (and happening to end up with largely duplicate language) then this possible misreading of the English (not the underlying language) would be understandable, and follow the general theory that Joseph participated in the translation of the text.
Tvetdnes’ alternative hypothesis relies heavily upon the Hebrew:
"Upon closer examination, however, one notes that the KJV/MT (Masoretic text) is gibberish at this point and requires some correction. We probably have a case of double haplography. To illustrate, let us reproduce here the Hebrew of MT and a Hebrew translation of [the Book of Mormon]:
MT: l- ‘py clyzy g’wty
BM: l’ ‘py cl clyzy gywty
The MT scribe, or a predecessor, has – perhaps after a long tiring day of work – made two deletions here. Firstly, he deleted the Hebrew letter aleph (’) from the negative particle, thus producing the preposition l-. Because the earliest Hebrew writing has no spaces to divide words, the mistake would have been even easier. The second deletion involved the preposition cl (“upon”). Both of these cases of haplography occurred because of the proximity of other identical alphabetical elements to those which were deleted (’ being followed by ’ and cl being followed by cl). The reconstructed Hebrew sentence based on the reading of the BM (with “for” added at the beginning for English style) thus reflects an older version of Isaiah for [the brass plates] than for the MT (especially notable since MT/KJV is nonsensical anyway.)" (Tvedtnes, 1981, pp. 52-3.)
The more technical explanation is interesting because it uses the Book of Mormon text to reconstruct an earlier Hebrew text, and then find a logical reason for the deletion of the phrase in the text underlying the KJV. This ability to find a reasonable reading for a partially nonsensical MT text gives this reading a higher possibility. However, it must still be remembered that the first explanation also can fit into Joseph’s probable translation scheme.