"You shall not eat any meat that is torn in the field"—Exodus 22:30.
It is forbidden to consume the flesh of an animal that has been attacked by another animal and sustained life-threatening injuries, or an animal that has sustained such injuries in another manner, even if it has been ritually slaughtered.
The fact that the Torah employs the words "in the field" when issuing this prohibition teaches us that certain other meats that have "left their natural borders" are also forbidden. This includes flesh of a sacrifice that has left its confines (e.g., the flesh of a "holy of holies" sacrifice that left the Temple Courtyard), and the fetus that has extended an arm [or leg outside his mother's womb and then its mother was slaughtered before it was born—this limb is forever forbidden for consumption].
This prohibition also includes any flesh torn from a living animal.