When Joseph Smith removed the clausal “it came to pass that” from this passage, he also changed the preceding conjunction and to now. For another example where Joseph deleted “it came to pass that” and also edited a preceding and to now (or perhaps to and now), see the discussion under Alma 14:5–6. The critical text will, of course, restore the original “and it came to pass that” here in Alma 24:21. For further discussion of the occasional removal of “it came to pass” from the text, see under come to pass in volume 3.
Summary: In Alma 24:21 replace Joseph Smith’s now with the original sentence-initial conjunction and; also restore the original “it came to pass that” clause.