The original text of the Book of Mormon frequently used the third person singular present-tense ending -eth with plural subjects, as here in the preface to 2 Nephi. This inflectional ending was removed in the 1920 LDS edition. The critical text will restore such usage. For complete discussion, see infl al endings in volume 3.
Summary: In accord with the earliest textual sources, the original -eth ending in the preface to 2 Nephi should be maintained; this verbal ending, characteristic of the biblical style, frequently occurs with plural subjects in the original text.