Not exactly famous quotes, but if anyone is familiar with the trading card game Magic: The Gathering, many cards come with "flavor text" which often just relates to the lore of the game. Occasionally, though, there are a few gems that deal with knives and edged weapons. Here are a few from over the years,
from the card Glorius Charge
One's blade is only as sharp as one's conviction.
from Leonin Scimitar
"Every scratch tells a story, and every notch has a name. Four generations have held this blade. You shall not disappoint them."
from Pardic Swordsmith
A finely crafted blade will never meet as many blows on the battlefield as it did on the anvil.
from Steelshaper's Gift
Some blades seek their own wielders.
from Trusty Machete
"Until this expedition is done, that blade is your guardian, your liberator, and your best friend all rolled into one."