Find an example of it then, because I was going to say the same thing yet couldn't find an example to back it up. I'm starting to think I imagined it. The closest I could find was what he said to Kaku at Enies Lobby, right before he used Asura, but even that was partially a play on words. "Suffering is welcome on the path of carnage."
Actually, the one about luck was in the manga. http://www.mangareader.net/103-2487-10/one-piece/chapter-380.html I think leaving it to luck fits pretty well with the argument that Zoro isn't just now believing in fate. Along with the sword incident in Loguetown.