Here the printer’s manuscript reads twice in the plural as “according to the words of Ammaron”. But the 1830 edition has for the first instance of this phrase the singular word. When Joseph Smith edited the text for the 1837 edition, he decided to follow the 1830 reading here, so in 𝓟 he crossed out the plural s for the first instance of words. But as explained under 3 Nephi 29:7, the text strongly supports the plural words in the phrase “according to the word(s) of X” whenever X refers to a human. Moreover, there is independent evidence that the 1830 compositor sometimes replaced words with word (for example, in Jacob 3:11). The critical text will therefore adopt the plural words for both instances of “according to the word(s) of Ammaron” here in Mormon 2:17.
Summary: Accept in Mormon 2:17 both instances of the plural “according to the words of Ammaron”, the consistent reading of the printer’s manuscript; for the first instance of words it appears that the 1830 compositor accidentally set word.