Here the original manuscript reads sware, but in copying from 𝓞 to 𝓟 Oliver Cowdery replaced the archaic, biblically styled sware with the modern English swore. In this case, the printed editions have maintained the modern swore, but the critical text will restore the original sware. For a complete discussion of the tendency in the history of the text to replace sware with swore, see under Enos 1:14.
Summary: Restore the original sware in Alma 25:1 since this is the reading of the original manuscript.