Isaiah 28:10 (King James Bible) for precept must be upon precept / precept upon precept line upon line / line upon line here a little and there a little
Isaiah 28:13 (King James Bible) but the word of the LORD was unto them precept upon precept / precept upon precept line upon line / line upon line here a little and there a little
The Book of Mormon text is a paraphrase of the two Isaiah passages. The repetition of “precept upon precept” and “line upon line” is omitted in the Book of Mormon text, and the order is reversed. In addition, the earliest text has an and between “line upon line” and “precept upon precept”. The 1830 typesetter omitted this and, although in this case it seems doubtful whether he would have done so by reference to his King James Bible. Joseph Smith, in his editing for the 1837 edition, crossed out the and in the printer’s manuscript, probably because the 1830 edition itself omitted it, although his possible familiarity by that later time with this Isaiah phraseology could have played a role. Joseph frequently edited the printer’s manuscript to agree with changes (including errors) that had earlier been introduced into the 1830 edition.
This same language from Isaiah 28 occurs twice in the Doctrine and Covenants. Yet in each instance, the text follows the order and the nonrepetitiveness of the Book of Mormon text rather than the King James language from Isaiah 28:
Consistent with the 1830 edition for 2 Nephi 28:30, these two quotes from the Doctrine and Covenants (the current LDS edition) also omit the and before “precept upon precept”.
On the other hand, the earliest text for 2 Nephi 28:30 demonstrates increased parallelism by having an and before the second and fourth lines (cited below), which is generally consistent with the increased parallelism of the Book of Mormon text when compared with the King James translation of Isaiah:
Summary: Restore in 2 Nephi 28:30 the earliest text, with its extra and (“line upon line and precept upon precept”), which allows an increase in parallelism with the following “here a little and there a little”.