Lady Justice's Sword
Lady Justice often carries a sword in one hand. The sword is a historical symbol of authority, wielded by kings, emperors and generals. It is therefore one of the earliest symbols for justice, as the power of a monarch could be delivered with a stroke of the sword. Additionally, the sword has an esteemed place in ceremony even today, as people who are knighted are touched upon the shoulders with a blade. Lady Justice's sword advances the concept that justice can be swift and final.
https://www.theclassroom.com/symbolism-of-lady-justice-12080961.html