Isaiah 9:9 (King James Bible) that say in the pride and stoutness of heart
The repeated the in the earliest Book of Mormon text, however unnatural for English speakers, better exemplifies the parallelism of conjuncts in the Book of Mormon text, as can be seen in the following example that also has “the pride” as a conjunct:
In the original Hebrew for Isaiah 9:9, neither pride nor stoutness takes the definite article, so a more literal translation would be “in pride and stoutness of heart”. By having the before each conjunct, the Book of Mormon text preserves some aspect of parallelism. In 2 Nephi 19:9, the 1837 edition removed the repeated the, thus making the text agree with the King James reading. Nonetheless, this omission of the the may have been accidental; its deletion was not marked in 𝓟 by Joseph Smith.
Here is another example of where the Book of Mormon text has a repeated the while the corresponding King James passage is missing it:
In this case, the original manuscript is extant and has the repeated the. Furthermore, this extra the has never been removed from this other passage. For discussion, see 1 Nephi 21:10.
Summary: Restore in 2 Nephi 19:9 the repeated the that is found in the earliest extant text, the printer’s manuscript (“in the pride and the stoutness of heart”).