Here in this part of Helaman 12, we have seven original occurrences of the Hebraistic if-and construction, whereas in English we expect if-then (or simply if without the then). These seven occurrences of the Hebraistic and are listed above as 1–4 and 6–8. In his editing for the 1837 edition, Joseph Smith removed all these and ’s (although he marked only one of these deletions in the printer’s manuscript). As explained under 1 Nephi 17:50, the critical text will restore all original instances of if-and, providing there is support in the earliest textual sources for the Hebraistic and. Note in particular that it would be difficult to claim here in Helaman 12:13–21 that this series of extra and ’s were all accidentally added during the early transmission of the text.
Nonetheless, in the middle of this series of if-and ’s, there is one exceptional case (in verse 18, listed above as 5) for which the earliest textual source (the printer’s manuscript) does not have the if-and construction; instead 𝓟 reads without the extra and. It could well be that the original text here actually read “and behold it shall be accursed”. But elsewhere in the earliest text, there is evidence that the use of Hebraistic and is selective, sometimes occurring and sometimes not. In one case, when copying from 𝓞 into 𝓟, Oliver Cowdery accidentally removed one of these Hebraistic and ’s, replacing “and it shall be earth” with “it should be earth” (omitting the and and replacing the shall with should ):
Yet in 1 Nephi 17:50, there are actually three if- clauses, two without the and and one with it, at least in the earliest textual source (in this case, the original manuscript):
Similarly, in Helaman 10 there is a passage with two instances of the Hebraistic ifand, but those two instances are followed by an if- clause for which the following main clause lacks the and:
Some of these cases without the and do not involve a direct quote (namely, the first and third examples in 1 Nephi 17:50 and the last one in Helaman 10:8–10), but that difference serves as only a partial explanation since the and is lacking, for instance, here in Helaman 12:18 (the one with the fifth if- clause); in this case, we have a direct quote. Basically what we see is that in each of three different passages (1 Nephi 17:50, Helaman 10:8–10, and Helaman 12:13–21) there are exceptions to the Hebraistic if-and construction. This exceptionality implies that the variability is inherent. In fact, the Book of Mormon text has numerous examples of if-clauses that have no Hebraistic and for the following main clause. Based on this variability, there is no compelling reason to suppose that Helaman 12:18 or Helaman 10:10 or the two cases in 1 Nephi 17:50 originally had a Hebraistic and. For further discussion of the Hebraistic and, see under hebraisms in volume 3.
Summary: Restore each of the seven cases of original if-and in Helaman 12:13–21 but leave the one case (in Helaman 12:18) where the Hebraistic and is lacking in the earliest textual source (here the printer’s manuscript).