A sword is never sheathed
Until it has tasted blood.
A good swordsman
Is seldom seen with a sword.
Many centuries ago, there was a wanderer who was constantly chased by assassins. He was the best swordsman in the country. His challengers wanted to overcome him and thereby establish their own fame. Although the swordsman had long ago repented his killing and had renounced his status, he was still considered the best.
Over and over, his enemies came for him, and just as many times he defeated them using things at hand — umbrella, fan, sticks. He did not draw a real sword for he knew he was far too lethal when armed.
So it is that the wise remain humble so that others are not aroused against them. They avoid conflict whenever possible. If trouble comes to seek them, they use only the bare amount of force in return. To go further is to fall into excess.