In the Book of Mormon text, the historical third person singular ending -(e)th is often found for verbs taking plural subjects, usually third person plural forms, but occasionally with second person plurals (as discussed under Alma 41:9). Here in Helaman 13:34 we have a case where the subject is the first person plural pronoun we. Joseph Smith replaced this instance of we layeth to we lay in his editing for the 1837 edition, but the critical text will restore the original we layeth. For cases where the -(e)th originally occurred with the first person singular pronoun I, see under 2 Nephi 4:15. For a general discussion, see under infl al endings in volume 3.
Summary: Restore in Helaman 13:34 the -(e)th ending for the first person plural subject pronoun we; such extensions of the historical third person singular ending can be found throughout the original Book of Mormon text.