The 1858 Wright edition inserted the perfect auxiliary have in this sentence. This error is most probably a typo since in the next verse the same use of the past-tense said was left unchanged in that edition:
There would have been no motivation for the 1858 typesetter to consciously insert the have in verse 2 but not in verse 3.
Summary: Maintain the use of the past-tense said in 2 Nephi 32:2.