As discussed under Alma 34:30, the word scriptures sometimes acts as a single semantic unit. Thus here in 3 Nephi 28:33 the earliest text reads “all the scriptures which gives an account”, just as Alma 34:30 originally read “the holy scriptures testifies”. In his editing for the 1837 edition, Joseph Smith emended the third person singular verb form ending in -(e)s by removing it, giving testify in Alma 34:30 and give in 3 Nephi 28:33. The critical text will restore the original nonstandard grammar in both cases since it appears to be fully intended.
Summary: Restore in 3 Nephi 28:33 the third person singular form gives, the reading of the earliest textual sources (𝓟 and the 1830 edition); this kind of subject-verb agreement for the plural scriptures occurs elsewhere in the earliest text (namely, in Alma 34:30).