Here we have two minor manuscript corrections. The first one is found in 𝓞, where Oliver Cowdery initially wrote “the words of God”. He immediately deleted the plural s, apparently by erasure (the s is smeared). Oliver then wrote inline the following of, with the o overwriting the last part of the erased s. The following singular pronoun it supports the singular usage (“but that it might go forth throughout all the land”). As explained under Alma 5:11, either reading (with word or words) is theoretically possible here, so we follow the earliest textual evidence, in this case the corrected reading in 𝓞.
The second scribal error occurred as Oliver Cowdery copied the text from 𝓞 into 𝓟, where he initially wrote “throughout all his land”. Virtually immediately Oliver crossed out the initial his and supralinearly inserted the without any change in the level of ink flow. 𝓞 is not extant for this word, but it probably read the. Most likely, Oliver’s initial error in 𝓟 was the result of the following occurrence of his: “that his people might be convinced”. Theoretically, either the or his is possible in this construction. Normally the text has “through(out) (all) the land”—that is, the determiner is the. In two cases, the determiner is this (Mosiah 1:10 and Alma 5:5); but in one case, the determiner is his:
The correction of his to the in Alma 23:3 suggests that in Alma 47:1 the use of the his in “throughout all his land” could be an error for the, with the his coming from the following “among all his people”. But since other determiners are always possible for this construction involving throughout and land, the critical text will follow the earliest textual sources in selecting the determiner for land. Since in Alma 23:3 the correction of his to the is virtually immediate in 𝓟, the critical text will accept the the. On the other hand, in Alma 47:1 the his in “throughout all his land” will be maintained since 𝓟 reads that way (in this instance, 𝓞 is not extant for the determiner of land ).
Summary: Accept in Alma 23:3 two corrections in the manuscripts: “the word of God” in 𝓞 and “throughout all the land” in 𝓟; usage elsewhere in the text supports these two corrections.