Here in the printer’s manuscript, Oliver Cowdery initially wrote “to the land of Middoni” instead of “from the land of Middoni”, probably in anticipation of the to in the following “to the land of Ishmael”. His correction of to to from is virtually immediate; there is no change in the level of ink flow for the supralinear from. Earlier in the text, Alma 17 identifies the land of Ishmael, under king Lamoni, as the land that Ammon entered to preach the gospel; and Alma 20 refers to the land of Middoni as the land where Ammon and Lamoni went to release Ammon’s brethren.
Summary: Maintain in Alma 21:18 the corrected reading in 𝓟, the preposition from rather than to in “from the land of Middoni”.