When two men fight, and one of them pushes a pregnant woman and a miscarriage results, but no other damage ensues, the one responsible shall be fined … But if other damage ensues, the penalty shall be life for life, eye for eye, tooth for tooth, hand for hand, foot for foot, burn for burn, wound for wound, bruise for bruise. (Exodus 21:22-25)
The text describes a scene in which a pregnant woman is in the wrong place at the wrong time, and she is accidentally injured. But what sort of injury is it? The Torah portion considers two cases: first, that the trauma is to the fetus, and the injury causes the woman to miscarry; second, that the trauma results in some other kind of injury to the woman herself.
In the history of Jewish interpretation, these verses have been understood to indicate a clear distinction between the potential life of an embryo or fetus, and the life of a living human being like the pregnant woman. The distinction is seen in the difference between the punishments: in the first scenario the penalty for the loss of the fetus is only monetary, while in the second scenario the death of the pregnant woman would be a capital crime. That essential distinction — that a fetus, while precious, is not equivalent to a fully formed human life — lays the foundation in later Jewish law for a relatively permissive view of abortion. Because pikuach nefesh, the “saving of a human life,” always takes precedence in Jewish law over other concerns, the morality of abortion in Judaism is always tied to the welfare of the pregnant woman.