Apocalypse Revealed#592
592. Anyone who kills with the sword must be killed with the sword. This symbolically means that someone who uses falsities to destroy another's soul is destroyed by falsities and perishes.
Swords symbolize truths, and in an opposite sense, falsity, in both cases combative (no. 52, 836). Thus to kill means, symbolically, to destroy or to cause to perish, and to be killed means to be destroyed or to perish, both of which are occasioned by falsities.