The 1858 Wright edition replaced “into that land” with “into the land”, perhaps because of the preceding “the land of Jershon” or the following “the city”. The 1874 RLDS edition restored the original that, the reading of the 1840 edition (the 1874 RLDS edition derives from both the 1840 edition and the 1858 Wright edition). Either reading is theoretically possible, so we follow the earliest extant source (in this case 𝓟).
Summary: Maintain in Alma 43:25 the determiner that in the phrase “into that land”.