Who said....

There's another similar thread with descriptions of locations (called, appropriately enough, Locations) and I thought this might interest people. Guess who said this, and to whom:

"The treacherous are ever distrustful. But you need not fear for your skin. I do not wish to kill you, or hurt you, as you would know, if you really understood me."

Not too tough. Figure it out and answer with another quote!