The Mishnah rarely cites biblical sources for its laws. For example, the mishnah on today’s daf states:
These are are saved from transgressing even at the cost of their lives: One who pursues another to kill them, or pursues a male to sodomize him, or pursues a betrothed young woman to rape her.
In most instances, if we become aware that someone is about to commit a transgression, it is our obligation to warn them against proceeding. However, this mishnah teaches, in the extreme cases of murder and rape, there may not be time for discussion. If that is the case, bystanders are obligated to intervene — even to the point of killing the aggressor.
It is the Gemara, not the Mishnah, that seeks to attach this rule to a biblical source. The Gemara begins by citing a beraita that suggests a derivation:
From where is it derived that with regard to one who pursues another in order to kill him, the pursued party may be saved at the cost of the pursuer’s life? The verse states: “You shall not stand idly by the blood of another.” (Leviticus 19:16)
Logically, this verse, which states that one should not stand idly by when another’s life is in danger, is a strong match for the mishnah’s law. But the Gemara is not certain that this is the correct verse to support the mishnah — not because of a problem with the interpretive logic, but because the verse has already been used to support a different law, one which requires people to save those who are being drowned, dragged away by wild animals or attacked by bandits.
What these two laws have in common is that they describe situations in which a person will suffer great harm without intervention and both laws compel the onlooker to take decisive action. This, the Gemara concludes, is what we learn from Leviticus 19:16’s injunction not to stand idly by the blood of another.
Now the rabbis want to understand where the Torah teaches that lethal force is permitted to prevent an imminent murder or rape. For this, the Gemara turns to Deuteronomy 22:25–27:
If the man comes upon a young, betrothed woman in the open country, and the man lies with her by force, only the man who laid with her shall die; you shall do nothing to the young woman because the young woman has committed no sin worthy of death. For as when a man rises against his neighbor, and slays him, so too with this matter. He found her in the field, and the betrothed young woman cried out, and there was none to save her.
The Torah asserts that there was no person in the vicinity to save the woman from her attacker. Therefore, the rabbis reason, if someone is in the vicinity trying to save her:
He must do so by any means.
It is from this that the rabbis learn that one can, indeed should, use lethal force — the ultimate means — to prevent the rape of a betrothed woman.
But what about using lethal force to prevent murder? Embedded within this paragraph in Deuteronomy is an aside about murder that seems a bit out of place. According to the school of Rabbi Yishmael, the juxtaposition of the two crimes, rape and murder, teaches that what is true of one is true of the other: Lethal force, he concludes, can be used to prevent both.
The lines between the biblical text and rabbinic law are not always straight ones. Some suggest the Gemara preserves an earlier rabbinic process of deriving law from the Torah. Others suggest that the rabbis of the Talmud had before them two texts they needed to reconcile: the Torah and the Mishnah. The Talmud, on this view, is (in part) a record of their attempt to connect the two retroactively; showing how every law in the Mishnah is in fact supported by the scripture. Both models have value. If we accept the first model, it can be bracing to imagine that the rabbis of the Talmud present to us an accurate picture of how the Judaism that they knew came to be. And if we lean toward the second, it might be empowering to think that the rabbis were doing the best that they could to figure it all out, just like we are. And to marvel at how they succeeded.
Read all of Sanhedrin 73 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on February 28, 2025. If you are interested in receiving the newsletter, sign up here.
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