In the printer’s manuscript, Oliver Cowdery initially wrote the singular word; then later (with somewhat heavier ink flow) he inserted the plural s at the end of word. The original manuscript is not extant here, but Oliver was probably correcting to the reading of the original manuscript. He may have initially written the singular word because of the following singular was (“the word of Abinadi was brought to pass”). Even so, it should be emphasized here that one cannot use the occurrence of the singular verb was in the original manuscript as evidence for the singular subject word since the plural noun words frequently took a singular verb in the original Book of Mormon text; in fact, in two cases (each marked below with an asterisk) there is a postmodifying prepositional phrase “of X”, just like here in Alma 25:9:
And in one of these cases, Oliver Cowdery made the same initial mistake that he apparently made here in Alma 25:9:
𝓞 is not extant in this case either. But for this part of the text (from Helaman 13 through the end of Mormon), both 𝓟 and the 1830 edition are firsthand copies of 𝓞; and in this case, the 1830 edition reads “words … was”, while in the printer’s manuscript Oliver initially wrote “word … was” but then virtually immediately inserted the plural s at the end of word (there is no change in the level of ink flow), giving “words … was” (the same as the 1830 reading).
In virtually every instance the Book of Mormon text refers to Abinadi’s word(s) in the plural (25 times, including here in Alma 25:9). Only in one passage is the singular word used to refer to Abinadi’s message:
The original manuscript is not extant for any of the book of Mosiah, so we cannot be sure if the singular is correct in Mosiah 17:11. In fact, the preceding verse uses the plural:
The critical text nonetheless accepts the singular word in Mosiah 17:11 since either word or words can be used in such contexts. Consider, for instance, the following variation with respect to Alma’s word(s):
Thus the singular or plural usage is quite possible; so in each instance we let the earliest textual sources determine which number, singular or plural, is correct for word. Here in Alma 25:9, we accept the plural words and the singular was.
Summary: Accept in Alma 25:9 Oliver Cowdery’s corrected reading in the printer’s manuscript (namely, the plural words); also restore the original singular verb form was, despite its ungrammaticality in standard English (“thus the words of Abinadi was brought to pass”).