From Meet the Press (via Mike Allen):

PETRAEUS: “I just read a book about Kipling in India, of all things. And most recently, I’ve been reading about the historiography of [Union commander and later president Ulysses] Grant, how historians changed their views of Grant over the years, initially of course regarding him as the, a true hero of course and then over time, in the 1900s, there was a period when a bit more disparaging views of him and it’s actually come up again in recent years.
GREGORY: “Funny you should say that because I had this quote prepared for you from someone that you admire. It is this: ‘I am not a politician, never was, I hope never to be.’ Do you know who said that?”
PETRAEUS: “Was it Grant?”
GREGORY: “It was Grant.”
PETRAEUS: “Well, I am not a politician and I will never be. (Laughs.) I say that with absolute conviction.”
GREGORY: “Well that’s what he said. But does that mean that you are totally clear that you’ll never run for president?”
PETRAEUS: “Yeah, I really am. And, you know I’ve said — that I’ll adopt what Sherman said, and go back and look at what has come to be know as a ‘Shermanesque’ answer of that particular question.”
GREGORY: “No way, no how?”
PETRAEUS: “No way, no how.”