In his editing for the 1837 edition, Joseph Smith appears to have changed the which here to That, although he wrote the That at the end of the previous chapter—namely, at the end of the previous line in 𝓟 instead of supralinearly:
Joseph also enclosed the That in a box and, as noted, capitalized the initial t of the word. This change seems quite different from how Joseph usually made changes in the printer’s manuscript. Maybe he had some other intent in writing the That, especially since the which itself was never crossed out.
In any event, the 1837 edition ignored this change, perhaps because it just wasn’t noticed. And given other examples in the text, it was just as well. Overall, there are 17 occurrences in the original text of “these are the words which … ” , but there are no occurrences of “these are the words that … ” ; nor in any of these cases has which ever been grammatically emended to that except possibly here in Alma 10:1. The original text of the Book of Mormon has many examples of which used as a restrictive relative pronoun. So the failure to implement Joseph Smith’s change here is appropriate, given the usage throughout the Book of Mormon. For further discussion, see under which in volume 3.
A common prescriptive rule states that which should not be used as a restrictive relative pronoun; instead, that is preferred. This rule is unsupportable by actual usage and even contradicted by the usage of some well-known grammar gurus who claim the rule. For discussion and examples, see under that 1 in Merriam Webster’s Dictionary of English Usage.
Summary: Retain the original phraseology “these are the words which … ” in Alma 10:1; the use of which as a restrictive relative pronoun is very common in the original (and current) text of the Book of Mormon.