One Piece Chapter 48, page 4: GIVE UP ON THAT SEA

RED-LEG ZEFF, YOU'RE A MAN WHO ONCE BRAVED THE WATERS OF THE DEVIL'S HIDEOUT, THE GRAND LINE ITSELF! NOT ONLY THAT, YOU RETURNED WITHOUT INJURY. YOU MUST'VE KEPT A LOG DURING YOUR TIME IN GRAND LINE. SO WHAT I'M GETTING AT IS... HAND OVER THAT LOG TO ME!" Luffy is amazed, asking, "COOL, YOU'VE BEEN TO GRAND LINE, OLD MAN?" Zeff confirms he kept a log and still has it, but firmly refuses: "BUT I SHAN'T HAND THAT OVER TO YOU. THAT LOG IS THE PRIDE OF ME AND MY MEN WHO BRAVELY VENTURED GRAND LINE TOGETHER. IT'S MUCH TOO VALUABLE TO GIVE TO THE LIKES OF YOU!