One Piece Chapter 3, page 17: Chapter 3: Enter Zolo: Pirate Hunter

Zolo asks Luffy to feed him the dirty, trampled rice ball. Luffy is shocked, pointing out it's mostly dirt, but Zolo fiercely demands to eat every single grain. Zolo chews and swallows the dirty rice ball, coughing violently from the dirt. Despite the pain, Zolo tells Luffy to tell the little girl that he ate it all and that it was delicious. Luffy smiles warmly and laughs.