As discussed above, Joseph Smith altered this passage in his editing for the 1837 edition by replacing the that-clause with an infinitive clause. In addition, the definite article the was inserted in the 1837 edition before “rough places” but not before “smooth places”, which implies that the addition of the the was unintentional. Joseph did not add the the in 𝓟 when he edited the text for the 1837 edition.
Summary: Remove the definite article the that was added before “rough places” in the 1837 edition.