For the 1837 edition, Joseph Smith edited hath to has, but the 1849 LDS edition restored the original hath (probably accidentally), with the result that all subsequent LDS editions have had hath in this passage. Virtually all other instances of Joseph changing hath to has have been retained in the text unless the has itself was a grammatical error and was later replaced (usually by the plural have). The critical text will, in each case, follow the earliest textual sources in determining whether the reading should be hath or has. For further discussion, see infl al endings in volume 3.
Summary: Maintain in Mosiah 7:29 the original hath, the reading of the earliest textual sources.