Here in Alma 63:10 the original text uses two demonstratives, those and that: “unto those people which had gone forth into that land”. These demonstratives connect the text to the previous verse: “and it came to pass that in this year there were many people which went forth into the land northward” (Alma 63:9). Here in verse 10, the 1830 typesetter accidentally replaced the first demonstrative, those, with the, and all the printed editions have continued with that secondary reading. The critical text will, of course, restore the reading of the two manuscripts. For two examples where Oliver Cowdery made this same mistake in the manuscripts, but only initially, see under Alma 58:31.
Summary: Restore the original demonstrative those in Alma 63:10 (“unto those people which had gone forth into that land”).