Apocalypse Revealed #308
308. And there was given to him a great sword. This symbolizes the destruction of truth by the falsities accompanying evil.
It may be seen in no. 52 above that swords symbolize truth combating falsities and destroying them, and in an opposite sense, falsity combating truths and destroying them. The great sword here symbolizes the falsities accompanying evil destroying the truths accompanying goodness.
We say the falsities accompanying evil, because there are falsities that are not connected with evil, and these do not destroy truths, as those accompanying evil do.
That this is the symbolic meaning of the great sword is apparent from the fact that a black horse is seen next, which symbolizes an understanding of the Word extinguished as to truth, and truth is extinguished only by evil.