Isaiah 7:25 (King James Bible) and on all hills that shall be digged with the mattock there shall not come thither the fear of briars and thorns
The italicized on of the King James text was omitted in this verse. This difference appears to be intentional, although the resulting reading seems somewhat more awkward than the original King James reading.
The 1858 Wright edition inserted the definite article the before hills. This change is probably a typo, although “all the hills” does seem to flow more naturally than “all hills”. In any event, this reading with the intrusive the was not copied into the 1874 RLDS edition.
Summary: Maintain the earliest text for 2 Nephi 17:25: namely, the italicized on of the King James text is omitted and there is no definite article the before hills.