There are two related issues involved in this passage. First of all, one wonders if the use of them at the end of each verse isn’t a mistake for him, especially since the rest of this passage otherwise uses the singular pronoun he for the antecedent whoso. Second, the passage has some variation regarding whether the present-tense indicative verb forms in this passage should take the -eth ending.
We take up the second issue first. Near the beginning of verse 40, the printer’s manuscript has establisheth, but the 1830 edition has establish. The reading of the printer’s manuscript, establisheth, assumes that this main verb has been conjoined with shall declare rather than with declare alone. The 1830 reading assumes that the shall has been ellipted in the conjoined clause.
When we consider all the other examples of conjoined verbs in whoso(ever) noun clauses, we find that in 20 cases whole verb phrases are conjoined. In only one other case is the helping verb ellipted:
This one example is different because the negative not includes both repent and come; that is, the meaning is ‘whosoever will not repent and will not come unto my beloved Son’.
Typically, when there is a modal verb, that helping verb is repeated in the conjunct:
But there is one important counterexample that occurs later in 3 Nephi:
This example parallels the reading of the printer’s manuscript for 3 Nephi 11:40. The first conjunct has the modal verb will, but the verb in the second conjunct ends in -eth. This example argues that the original manuscript for 3 Nephi 11:40 could have read establisheth rather than establish. Moreover, the use of establisheth is supported by “the same cometh”, “he buildeth”, and the original “the gates of hell standeth open” later on in the verse. The editors for the 1920 LDS edition changed standeth to stand in accord with standard English: the present-tense -eth ending is supposed to occur with only third person singular subjects. As discussed under the phrase “Nephi’s brethren rebelleth against him” in the 1 Nephi preface, the Book of Mormon had numerous instances of this plural usage in the original text (in fact, some are still in the current text). In each case, the critical text will restore or maintain such usage. Also see the discussion under infl al endings in volume 3.
When we consider early errors in transmission, we find that Oliver Cowdery sometimes added the -eth ending:
On the other hand, there are two instances where the 1830 typesetter removed the -eth ending:
(The second of these is complicated by the occurrence of the preceding doeth, which was edited to doth by the 1830 typesetter. For discussion, see under that passage.) From a transmission point of view, either Oliver or the 1830 typesetter could be responsible for the variation for establish(eth) here in 3 Nephi 11:40. So we follow the internal evidence in this case, which supports the reading establisheth rather than establish. Of course, the earliest textual sources support standeth.
We now turn to the question of whether the pronoun at the end of verses 39 and 40 should be him rather than them. These two object pronoun forms, them and him, have sometimes been mixed up in the transmission of the text since in colloquial spoken pronunciation both are pronounced as /ßm/ (for the manuscript evidence, see under 1 Nephi 10:18–19). Under Mosiah 5:10, I note that for whoso(ever) the pronominal referent can be either the singular he or the plural they. Here in 3 Nephi 11:40, the use of them at the end of that verse seems odd since earlier in the verse the reference is to he (“but he buildeth upon a sandy foundation”).
Still, there is the use of such in the next clause (“and the gates of hell standeth open to receive such”). In the Book of Mormon, the noun such typically implies a plural. In fact, in certain cases the preceding text may use the singular pronoun he, but then after an instance of such the text uses they:
So at least here in 3 Nephi 11:40 the use of them after such is acceptable (“and the gates of hell standeth open to receive such when the floods come and the winds beat upon them”).
Also note that other quotations referring to building one’s house on a rock or on sand support the use of the plural them. We have the following additional example in the Book of Mormon:
Note that throughout this later passage whoso takes plural forms. We also have the following example from a revelation given to Joseph Smith sometime between the summer of 1828 and April 1829, after the first part of the Book of Mormon translation had been completed:
This second example starts out with him but switches to the plural them, thus paralleling the usage in 3 Nephi 11:40.
Consequently, the two occurrences of the plural them at the end of 3 Nephi 11:39 and 3 Nephi 11:40 are most probably correct. The critical text will retain both these instances of the plural pronoun, the reading in each case of both 𝓟 and the 1830 edition.
Summary: Maintain at the end of both 3 Nephi 11:39 and 3 Nephi 11:40 the plural pronoun them; restore the consistent use of the -eth ending in 3 Nephi 11:40, namely, establisheth (the reading in 𝓟) and standeth (the reading in both 𝓟 and the 1830 edition); evidence elsewhere in the text supports the multiple use of them and the -eth ending in this passage.