One Piece Chapter 52, page 12: OATH

Chef Zeff and the other Baratie cooks stand in awe, with Zeff remarking, "TO THINK THAT MIHAWK WOULD SAY SUCH A THING...". Johnny and Yosaku continue to tend to Zoro. Mihawk then turns his attention to Luffy and asks, "BOY, WHAT DO YOU AIM FOR?". Luffy sits up and boldly declares, "PIRATE KING!". Mihawk smiles slightly and replies, "A TOUGH PATH, INDEED. EVEN TOUGHER THAN SURPASSING MYSELF." Luffy sticks his tongue out playfully and retorts, "WHATEVER! I'M GOING TO DO IT ANYWAYS!".