Pesachim 25B

ושפיכות דמים.

or murder.

עבודה זרה ⁠— הא דאמרן. גילוי עריות ושפיכות דמים, דתניא, רבי אומר: ״כי כאשר יקום איש על רעהו ורצחו נפש כן הדבר הזה״. וכי מה ענין רוצח אצל נערה המאורסה?

That one may not heal oneself with idolatry even when his life is in danger is learned from that which we just said, based on the verse: “With all your soul and with all your might.” From where is this halakha derived with regard to forbidden sex and murder? As it was taught in a baraita that R' Yehuda HaNasi says: The verse says about one who rapes a betrothed woman: “But you should do nothing to the young woman; 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” (Deuteronomy 22:26). What does a murderer have to do with a betrothed young woman who was raped? Why would the verse mention murder in this context?

הרי זה בא ללמד, ונמצא למד. מקיש רוצח לנערה המאורסה: מה נערה המאורסה ⁠— ניתן להצילה בנפשו, אף רוצח ⁠— ניתן להצילו בנפשו. ונערה המאורסה מרוצח: מה רוצח ⁠— יהרג ואל יעבור, אף נערה המאורסה ⁠— תהרג ואל תעבור.

Rather, the mention of murder comes in order to teach a halakha about the betrothed young woman, and it turns out that, in addition, it derives a halakha from that case. The Torah juxtaposes a murderer to a betrothed young woman to indicate that just as in the case of a betrothed young woman one may save her by taking the rapist’s life, so too, one may save a potential murder victim by taking the pursuer’s life. Conversely, it is possible to learn about the case of a young betrothed woman from the case of a murderer. Just as with regard to a potential murderer the halakha is that if one is being forced to murder someone else, he should allow himself to be killed and not transgress that prohibition, so too, with regard to a betrothed young woman the halakha is that she should allow herself to be killed and not transgress the prohibition of forbidden sex.