Here in Alma 5:11, the printer’s manuscript originally read “the word of God”, which the 1830 compositor followed. But Joseph Smith added the plural s in his editing for the 1837 edition, undoubtedly because the immediately surrounding text uses plural forms (“the words which was delivered by the mouth of Abinadi … and my father Alma believed them”). Elsewhere the Book of Mormon text has many examples of the precise phrase “the word of God” (90 of them); but there are four examples of “the words of God”, and all of these are found at the beginning of the book of Alma:
Thus the suggestion that Alma 5:11 originally had the plural words in the expression “the word(s) of God” seems quite reasonable. But it should also be noted that the use of the singular word in “the word(s) of God” occurs 18 times in Alma 1–9 (not counting the instance here in Alma 5:11); in fact, there are three other occurrences of the singular “the word of God” in Alma 5. Thus the occurrence of “the word of God” is more prevalent than “the words of God”, even in this part of the text. Furthermore, later in this chapter of Alma, verse 13 uses the singular word to refer to Abinadi’s preaching: “he preached the word unto your fathers”. So the singular word in verse 11 may not necessarily be an error.
Elsewhere in the text, when the verb is speak (as in Alma 5:11), we have four examples of the “the word of God” as the direct object, but none with “the words of God”:
Still, there are examples of the verb speak occurring with “the words of the Lord” (1 Nephi 4:14, 1 Nephi 7:4, 2 Nephi 5:19, Helaman 13:5, and 3 Nephi 29:2), “the words of your Maker” (2 Nephi 9:40), and “the words of (Jesus) Christ” (2 Nephi 32:3, 3 Nephi 30:1, and Moroni 2:1), all of which contain the plural words. But there are also examples where speak occurs with the singular word: namely, “the word of the Lord” (2 Nephi 5:20, Jarom 1:9, and Helaman 10:12). Thus usage allows either the singular or the plural when the text refers to “speaking the word(s) of ”.
There is abundant manuscript evidence that the scribes frequently mixed up the number for word(s); consider, for instance, the following three cases of textual variance for the phrase “the word(s) of God”:
Another possible emendation for Alma 5:11 is that the pronoun them may actually be an error for him; that is, in the original text the last clause read “and my father Alma believed him”. Usually, the verb believe takes a direct object that refers to language rather than to persons: in 36 instances (including here in Alma 5:11), the referent is either word(s) or thing(s); in 11 instances, we have a more specific reference to scriptures, records, reports, or testimonies. But in a handful of cases, the direct object for believe refers to persons:
The examples in Ether 4:10, 12 show both types of direct objects being used in the same passage (“believeth not my words / believeth not my disciples” and “believe my words … believe me … believe me ... believe the Father”). As discussed under 1 Nephi 10:18–19, there is some evidence that scribes could mix up them and him since both are pronounced in casual speech as /ßm/.
So here in Alma 5:11 there are three possibilities. First of all, we can restore the earliest extant reading, despite the possible conflict between the singular word and the following plural pronoun them. Or we have a choice between two possible emendations:
The critical text will restore the earliest reading under the following reasoning. First, it is not necessary that the them at the end of Alma 5:11 specifically refers to “the word of God”; the them may actually be referring to the earlier use in verse 11 of “the words which was delivered by the mouth of Abinadi”. And even if them refers to “the word of God”, there is considerable evidence elsewhere in the text that pronouns may disagree in number with word(s) or with other nouns that refer to speech or writing. For a case where a singular pronoun can refer to either words or its equivalent things, see under 2 Nephi 33:4, which originally read “and the things which I have written in weakness will he make strong unto them / for it persuadeth them to do good” (the current text has words rather than things).
Summary: Restore in Alma 5:11 the earliest reading (in 𝓟 and the 1830 edition): “did he not speak the word of God and my father believed them”; there is support for such usage elsewhere in the text.