If men are gods, then in their hands are the tools they use to work their will. Zeus has thunderbolts. Thor has a hammer. And men in White Fang have whips, clubs and chains to make their will known. It hurts. A lot. And White Fang really, really hates it… so much that he mistrusts hands as a general principle, even if they don't have anything but treats in them: "There it came now, the god's hand, cunning to hurt, thrusting out at him, descending upon his head" (20.9). Poor White Fang doesn't realize he's about to get the first friendly pat he's ever felt in his life.
At the same time, the hands that punish can also reward. Scott makes his first real inroads with White Fang, first with meat in his hands—"The god merely held near to his nose a piece of meat" (20.5)—and then with the almighty scratch behind the ears, or, as our narrator puts it, "non-hostile pats" (20.12). Hands become the tools of the gods, and thus the way that White Fang best understands humanity and their intentions towards him, using the following key: hands with meat = good; hands with whips = bad.