Same here. I've read it a few times and I'm still stumped. This really was a bad chapter, though probably has to do with the translations. Maybe there is another translation that makes more sense?
It makes sense to me. He finishes the thought on page 19. He was saying, basically and figuratively, "the longer I live, the stronger I become. Because people are like swords."
@DBZ: Hanzo didn't know he and Mifune had ever even met. How could Pein?