We say binky free because it's an allusion to the story of the Rainbow Bridge. The idea is that all the pets that have passed are waiting for us in a green field that's across a "rainbow bridge" from heaven, where all they do is play, eat, and binky all day. One day the owner will join them in that field, and then they cross the Rainbow Bridge together into heaven. It's a very sweet story that can be comforting. In particular, when a rabbit has passed away that was ill or in pain, we can imagine that they are binkying with joy, no longer trapped in a body that's no longer working correctly. For most other pets, we say "run free," but because a binky is an expression of pure joy that only rabbits do, we say "binky free." :hearts