Gun Control in Halacha

If one comes to kill you, kill him first.

And furthermore, it is taught in a baraita: One may not sell weapons to gentiles or the auxiliary equipment of weapons, and one may not sharpen weapons for them. And one may not sell them stocks used for fastening the feet of prisoners, or iron neck chains [kolarin], or foot chains, or iron chains. This prohibition applies equally to both a gentile and a Samaritan...

Apropos the baraita that discusses the prohibition against selling weapons, the Gemara relates that Rav Dimi bar Abba says: Just as it is prohibited to sell to a gentile, it is prohibited to sell to an armed bandit who is a Jew. The Gemara clarifies: What are the circumstances of this prohibition? If the thief is suspected of killing, isn’t it obvious that it is prohibited? After all, he is the same as a gentile. Providing a Jew who might kill with weapons is no different from giving a weapon to a gentile, as in both cases one violates the prohibition: Do not place a stumbling block before the blind. And if he is a bandit who does not kill, why not sell to him? The Gemara answers: Actually, Rav Dimi bar Abba is referring to a bandit who does not kill, and here we are dealing with a bandit who steals, as sometimes he makes use of his weapon to save himself when he is caught. Consequently, it is prohibited to sell him weapons in case he kills with them in self-defense. § The Sages taught: One may not sell shields [terisin] to gentiles, despite the fact that they are used for protection, not to attack others. And some say: One may sell shields to them. The Gemara asks: What is the reason behind the opinion that prohibits selling shields to gentiles? If we say it is because they protect them in wartime, if so, then even wheat and barley should not be sold to them. Rav said: If it were possible to avoid selling produce to gentiles without incurring their animosity, indeed it would be prohibited to sell them. Since limiting sales to gentiles to such an extent would cause great harm, it is only prohibited to sell them shields. There are those who say: With regard to shields, this is the reason that one is not allowed to sell them to gentiles: As when their use of their weapon is finished in battle, they kill with these shields. And accordingly, the reason that some say in the baraita that one may sell shields to them is because they maintain that this is not a concern, as when their weapon is finished they flee, rather than use their shield as a weapon. Rav Naḥman says that Rabba bar Avuh says: The halakha is in accordance with the opinion cited as: Some say. Rav Adda bar Ahava says: One may not sell blocks [ashashiot] of iron to gentiles. What is the reason? It is because they forge weapons from them. The Gemara asks: If so, then even hoes and axes should not be sold to them, as they too can be used to forge weapons. Rav Zevid said in response: The ruling of Rav Adda bar Ahava was stated with regard to Indian iron, which is of a superior quality and used only for crafting weapons. The Gemara clarifies: And as for the fact that nowadays we do sell all weapons, Rav Ashi said: We sell the weapons to the Persians, who protect us.

(8) Even as it is forbidden to sell to idolaters things which uphold their hands to idolatry so it is forbidden to sell them things wherein there is a menace to the public, for instance, bears, lions, weapons, iron fetters, and chains; it is likewise forbidden to sharpen their weapons for them. And, everything which is forbidden to sell to an idolater is also forbidden to sell to an Israelite who is under suspicion that he might resell it to an idolater. It is likewise forbidden to sell instruments of harm to robbers who profess to be Israelites.

(9) Israelites living among idolatrous neighbors, with whom they made a covenant of peace, are permitted to sell weapons to the king's servants and militia, because they conduct war therewith against the country's enemies to save it, as a consequence whereof they protect the Israelites who dwell among them. A city wherein there is an established house of idolatry, one is permitted to pass by it without its boundaries, but is forbidden to enter it; if the idolatry is established without its boundaries he may enter it.

(12) It is forbidden to sell arms of any kind to heathen ; one should not sharpen their weapons; one should not sell them a knife — — or anything that is likely to be a public danger. Shields, however, may be sold to them, since they are used only for defense.

(13) Just as the sages have prohibited the sale of arms to a heathen, so have they prohibited selling the same to a Jew who sells to a heathen. On the other hand, weapons may be sold to the local citizens' force, since they protect the Jewish population.

As it is taught in a baraita that Rabbi Natan says: From where is it derived that one may not raise a vicious dog in his house, and that one may not set up an unstable ladder in his house? As it is stated: “You shall not bring blood into your house” (Deuteronomy 22:8), which means that one may not allow a hazardous situation to remain in his house.

(9) The sages also prohibited the breeding of swine in any place, or of dogs, unless they are chained. One may, however, breed dogs in a town near the border. A dog should be tied up by day and untied at night. The sages said: "Cursed be the man who breeds dogs or pigs," because the damage they do is substantial and frequent.

(4) There is no difference between a roof or anything else that is dangerous and likely to cause death to a person who might stumble. If, for instance, one has a well or a pit in his courtyard — — he must build an enclosing ring ten handbreadths high, or put a cover over it, so that a person should not fall into it and die. So too, any obstruction that is a danger to life must be removed as a matter of positive duty and extremely necessary caution.

(8) Likewise, one has a positive duty to remove and guard oneself of any life-threatening obstacle, as it is said "beware and guard your soul". If one did not removed said obstacles, one has cancelled a positive commandment and transgressed "do not bring bloodguilt" (Deut. 22:8).

(4) A man may not go out with a sword, nor with a bow, nor with a shield, nor with a round shield, nor with a spear. If he has gone out [with any of these] he is liable for a Chattat. Rabbi Eliezer says: They are ornaments for him. But the Sages say: They are nothing but an indignity, for it is said, "They shall beat their swords into plowshares, and their spears unto pruning-hooks; nation shall not lift up sword against nation, neither shall they learn war any more" (Isaiah 2:4).