How we cite our quotes: All quotations are from The Godfather.
Quote #4
CLEMENZA: Leave the gun. Take the cannoli.
Not exactly a profound quote, but maybe intelligent advice: In this case, the gun, presumably free of fingerprints, is left behind after killing someone, while the delicious cannoli is taken along. Just because you're a vicious murderer doesn't mean you need to abandon your appetite, apparently.
Quote #5
SOLLOZZO: I don't like violence, Tom. I'm a businessman; blood is a big expense.
Sollozzo highlights the fact that there's nothing actively malicious in the violence he commits, so you shouldn't take it personally. It's just a means he uses to get his job done, and a messy means at that.
Quote #6
MICHAEL: Where does it say that you can't kill a cop?
Michael is, to cite a cliché, "thinking outside the box." He wants to wipe out the corrupt cop Captain McCluskey because the Corleones are just too far down in the count. Yet directly attacking an authority figure is more dangerous than killing other gangsters because it poses a greater threat to society.