In his editing for the 1837 edition, Joseph Smith reduced the conditional clause “if it so be that” to simply if. Such stylistic editing was obviously not necessary. The original text had 39 occurrences of this longer phrase, of which two instances have been deleted because of redundancy (see the discussion under 1 Nephi 14:1–2). None of the other examples of “if it so be that” have been deleted from the text, including the following instances that are similar in construction to 2 Nephi 9:29:
The critical text will therefore restore the full if-clause in 2 Nephi 9:29.
Summary: Restore the full clausal phrase “if it so be that” in 2 Nephi 9:29; the reduction of this clause for the 1837 edition to simply if appears to be based on stylistic considerations.