shabbat 3

the body is fixed but the hands, being neither public or private, can wander.

or: why the rabbis don't like doing the hokey-cokey on shabbat

(continuing the discussion about carrying, compares a body being laden up by someone else then walking out into the public space - which is definitely forbidden - to a hand that extends out from private to public while holding something. for english translation of this full talmud page see here)