Two Hebrew words in these verses need additional translations to better understand the meaning of the text. The first is  מַּחְתֶּרֶת (MAḤTERET) – herein translated as ‘tunneling.’  Additional meanings are underground organization, that operates covertly.  From the same root come words that mean: to strive, to conspire, to undermine, to subvert. 

The other word is דָּמִים (DAMIM), simply bloods (the plural of blood).   Another meaning is money, fee, or price.  Knowing these additional meanings is important to understand how the Jewish law of self-defense was derived out of these verses.  The Halakha, is not just the permission to kill the one that is about to kill you.  It also elaborates on the liability that goes with that permission, and the fences and limitations of using power in self-defense.

These two verses in Parashat Mishpatim (read my other essay on it here) create the basis to self-defense Halakḥa.  They translate into the phrase “If one comes with the intention to kill you, be quick and kill him first.” It is noteworthy to mention that it pertains not just the person under threat.  It connects to the obligation to save the lives of others even at the cost of killing the pursuer.

There are 150 commentaries on these two verses in Sefaria alone!  Mountains of text, laws and exegesis are found in Mishnah, Talmud and other Jewish literature.  We will review only a few that will allow us to better understand the meaning of these two verses.

Rashi (1040-1105) Commentary on Verse 1:

Rashi relies on Mishnah (Sanhedrin 8:6): ‘One who comes, undermining in covert, is sentenced on account of one’s final act.’

This [killing] is not regarded as a murder.  It is as though he [the thief] has been essentially dead from the beginning of his criminal act.  The Hebrew phrase אֵין לוֹ דָּמִים (Ein Lo Damim) is taken to mean: he, the thief, has no blood — no vitality – as if he is already dead.  Here Torah teaches the rule: “If one comes with the intention of killing you, be quick and kill him.”  

The same conclusion can also be derived from the other meaning of the same Hebrew phrase, Ein Lo Damim.  Meaning, there are no fees or payments (penalties) if the thief is harmed.

Rashi refers to Talmud (Sanhedrin 72a:4) that explains the abovementioned Mishnah when he comes to understanding the intent.  ‘This burglar in fact came with the intention of killing you.  He knew full well that no one can hold oneself in check, witnessing him stealing one’s property and doing nothing.  Therefore, he came with the determination that if the owner of the property would resist, he would kill him.’

Verse 2 – Fences and Conditions That Limit the Permission to Kill

Further down in the same page of the tractate (Sanhedrin 72a:15) the sages explain a fence to the former halakha.  What does it mean (verse 2) “If the sun is risen upon him, there shall be bloodguilt on his account”?  A question may be raised: did the sun rise only upon the burglar?  Rather, these words must be understood in a metaphoric sense.   If it is as clear to you as the sun that the burglar’s intention is to kill you, arise and kill him first.  But if you are not absolutely certain about his deadly intentions, do not kill him.

Rabbi Yaakov ben Asher (1269-1343) explains the same in a literal way.  The Torah assumes that if someone breaks into a house at night, he means and prepared to kill the owner.  If the owner kills the intruder, this is considered self-defense, even if the intruder had not yet harmed the owner.  However, if the intruder came by day, it is presumed that he had no intention to kill.  The burglar may assume that during the day the owner will be out of home, tending to one’s business.  If nonetheless, the owner killed the intruder, he is guilty of having shed the intruder’s blood.

The Halakha According to the Rambam (Maimonides)

The Rambam’s greatest composition is the Mishneh Torah (Review, Repetition, of Torah).  It is a fourteen volumes composition of an all-inclusive halakhic anthology of the entire system of Jewish law (Halakha).  The eleventh volume (Nezikim – torts) has a section called Theft; Chapter 9 therein deals with the issue at hand.  Rambam expands and clarifies the fences of this permission in a way that one can practically apply the halakha in real life situations.

One can kill a person who breaks into one’s home (or roof or courtyard) regardless the time of the day. Either the homeowner or another person may kill the intruder and are not liable for killing.  This applies any time, Shabbat included, without regard to the manner used to kill the intruder regardless gender and age.  

If it is clear that the thief only seeks financial gain and does not endanger life, one cannot kill him.  If the houseowner still kills the thief, this act constitutes a murder.  The same halakha applies regarding a thief who stole and departed, or catching the thief leaving the house without stealing.  A perpetrator turning away from the house and has no intent to kill its owner, cannot be slain.  Similarly, if people or witnesses surround the burglar, even within the domain he broke into, no one may kill him.  A court that finds that perpetrator guilty would not apply capital sentence upon him. So much more so, the people that witness that person trying to leave the premises. 

A person that covertly [at night] breaks into a garden, a field, a pen and such, may not be killed. The prevailing presumption is that he came to steal tangibles only and has no intent to kill the owner.  Afterall, the burglar assumes that the owner will not be present in such places [at night]. 

Extending Self-Defense – the Law of Pursuer (Din Rodef)

Mishnah and Talmud

Immediately following this discussion, the Talmud continues to expand the scope of self-defense to defending others.  Again, the discussion starts with quoting the Mishnah (Sanhedrin 8:7) and then expanding on it.

And these are the ones who are saved from transgressing even at the cost of their lives; that is to say, these people may be killed so that they do not perform a transgression: One who pursues another to kill him, or pursues a male to sodomize him, or pursues a betrothed young woman to rape her.

The Talmudic sages tried, and succeeded, in finding the substantiation for this ruling in Torah (Sanhedrin Pg 73a:2-3)

The Sages taught in a Baraita: From where is it derived that regarding 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 upon [by] the blood of another” (Leviticus 19:16 לֹא תַעֲמֹד עַל דַּם רֵעֶךָ אֲנִי יְהֹוָה׃); rather, you must save him from death.

The Gemara asks again: But from where do we derive that one may be saved at the pursuer’s life cost?  It is derived by an a fortiori inference from the case of the assaulted betrothed woman by a rapist.  If in the case of a betrothed young woman, whom the rapist comes only to degrade, and not kill her, the Torah said that she may be saved even at the cost of the rapist’s life, then in the case of one who pursues another person to kill him, all the more so should one say that he may be saved even at the cost of the pursuer’s life.

The Halakha According to the Rambam’s Mishneh Torah

We read in Mishneh Torah, Nezikim, Murderer and the Preservation of Life 1:14-16:  “Whenever a person can save another person’s life, but he fails to do so, he transgresses a negative commandment:  Leviticus 19:16 states: “Do not stand idly by while your brother’s blood is at stake.”  Similarly, this commandment applies when a person sees a colleague drowning at sea or being attacked by robbers or a wild animal, and he can save him himself or can hire others to save him.”

Rambam acknowledges that transgressing these prohibitions is less severe because it is not a result of a forbidden action.   Yet, he warns that “they are nevertheless very severe.  For whoever causes the loss of a soul of Israel is considered as if he destroyed the entire World.  And whoever saves a single soul of Israel is considered as if he saved the entire world.”

It is interesting to note, that Rambam uses the same argument of Rodef, Pursuer, to allow abortion (ibid, Halakha 9).  “This, indeed, is one of the negative mitzvot – not to take pity on the life of a Rodef (pursuer).  On this basis, our Sages ruled that when complications arise and a pregnant woman cannot give birth, it is permitted to abort the fetus in her womb, whether with a knife or with drugs.  For the fetus is considered a Rodef of its mother with its intent to kill her.”

Applicability of these Halakhot Today in Israel

The Rules of Engagement in Israel follow the rationale that our sages applied in setting the abovementioned Halakha:

Using firearms is permitted only if there is an assault that present an immediate and clear threat to one’s life.  It is also permitted if the assault is against others, but only if the police is not available to respond.  

One can not use firearms to protect property if risk of life or physical harm is not present.

The use of firearms for self-defense should be only as the last possible resort to defend one’s life.  Warning about the intent to use firearms should be considered, if such warning does not endanger the user.

Attempt to stop the perpetrator without killing should be considered, e.g. aiming to perpetrator’s legs. Cease fire immediately when the assault stopped and there is no more danger to life.

One cannot shoot an offender that runs away, unless s/he is still armed and may endanger others.

In 2008 the law was amended, to allow use of firearms if immediately needed to pushback one who forcefully breaks into a home or business.