Here the printer’s manuscript has the singular heaven, while the 1830 edition has the plural heavens. Nearby we can find some evidence that scribe 2 of 𝓟 tended to write the singular heaven in place of the correct heavens:
In this passage, the correct text is clearly “the heavens” since both the 1830 edition and the corrected reading in 𝓟 read this way. Of course, the case here in 3 Nephi 26:3 is more complicated since heaven was never corrected to heavens in 𝓟. And so it is theoretically possible that the singular is correct and that the 1830 typesetter made the change from an original heaven to the plural heavens.
Elsewhere in the original Book of Mormon text, there are numerous instances of “the heavens” (37 of them) but only two of “the heaven”:
Of the 37 other instances in the text, eight are of the form “the heavens and the earth”, so the plural is definitely favored here in 3 Nephi 26:3. In fact, note that in one of the exceptions (in Mormon 9:17), scribe 2 of 𝓟 initially wrote heavens (although as Havens), which he immediately corrected to the singular by erasing the plural s; the 1830 edition has the singular heaven, so 𝓞 must have read in the singular. Overall, of course, the plural “the heavens” is definitely favored. To be sure, the expectation of the plural could have prompted the 1830 typesetter here in 3 Nephi 26:3 to replace an original heaven with heavens (just like scribe 2 of 𝓟 almost did in Mormon 9:17).
There are four other occurrences in the Book of Mormon text referring to the earth passing away:
But none of these other passages include any reference to the heaven(s) passing away. In fact, it is possible to interpret 3 Nephi 26:3 so that it too does not refer to the heaven(s) passing away. David Calabro suggests (personal communication) that the phrase “and the heaven(s)” could be interpreted as a delayed conjoined subject that belongs to the previous clause:
And there are examples in the text of a noun phrase alone acting as a delayed conjoined subject:
Thus one could argue that here in 3 Nephi 26:3 there is one more reference to only the earth passing away. And one can find biblical support for the heavens being wrapped or rolled together as a scroll:
And this example supports the use of the plural heavens.
Nonetheless, there are several references to both the heaven(s) and the earth passing away in the King James Bible:
But these examples are not particularly helpful in determining the number for “the heaven(s)” here in 3 Nephi 26:3 since none are of the form “the heaven(s) and the earth”; when the definite article does occur, as in the last example, there is an intervening first. For the other passages we get simply “heaven and earth”—that is, without any article at all.
Interestingly, there is a biblical passage that lacks the reference to the earth passing away but does refer to “the heavens” passing away:
And as we have seen in the previous discussion, the language of this verse in 2 Peter 3 is earlier referred to in 3 Nephi 26:3 (namely, “even until the elements should melt with fervent heat”). Thus the use of the plural “the heavens” in 2 Peter 3:10 provides some support for the same plural reading in 3 Nephi 26:3:
This parallelism also provides support for interpreting “and the heavens” as belonging with the following clause (“and the earth should pass away”) rather than as a delayed conjoined subject attached to the preceding clause (“and the earth should be wrapped together as a scroll”).
But no matter how we parse “and the heaven(s)”, usage elsewhere in the Book of Mormon and in the King James Bible argues that the plural heavens is correct in 3 Nephi 26:3. The plural heavens was most likely the reading in 𝓞; while copying from 𝓞 into 𝓟, scribe 2 of 𝓟 seems to have dropped the plural s in heavens.
Summary: 3 Nephi 26:3 apparently read “the heavens” (the 1830 reading) in the original manuscript; the evidence for the plural reading is enhanced by the plural heavens in 2 Peter 3:10 (“the heavens shall pass away”), a New Testament phrase that is cited earlier in this verse; usage elsewhere in the Book of Mormon text as well as in the King James Bible favors “the heavens” over “the heaven”.