Oliver Cowdery’s addition of words could have been due to editing since what scribe 2 of 𝓟 wrote (“I have spoken these unto you”) definitely seems strange. Another possibility, if Oliver himself thought up the emendation, would have been to insert the word things. Usage in both the Book of Mormon and the King James Bible supports the phraseology “to speak these words” or “to speak these things”, with the following statistics for those cases where these words or these things serves as the direct object after the verb speak (here Alma 7:26 is excluded):
these words these things
the Book of Mormon 37 5
the King James Bible 18 6
But there are no instances of “to speak these” in either the Book of Mormon or the King James Bible; this result suggests that “I have spoken these unto you” is missing the head noun for its direct object. When we consider those specific cases where the direct object follows the verb speak, we get the following statistics for the small and large plates (once more Alma 7:26 is excluded):
these words these things
the small plates of Nephi 10 5
the abridged large plates of Nephi 27 0
Since Alma 7:26 is in the abridged portion of the large plates, these words is more probable than these things when the verb speak precedes. The critical text will therefore accept Oliver Cowdery’s correction in Alma 7:26. Even if 𝓞 itself read without words, Oliver’s correction (as an emendation on his part) would still probably be the original reading.
Summary: Accept in Alma 7:26 Oliver Cowdery’s inserted words, which was probably the reading of the original text (namely, “I have spoken these words unto you”) rather than the initial reading in 𝓟 (“I have spoken these unto you”) or the alternative emendation “I have spoken these things unto you”.