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. Abaye analyzes this baraita: What is the reason for the prohibition against selling these items to Samaritans? If we say that they are suspected of bloodshed, that is difficult: But are they suspected of this? Didn’t you say that one may seclude oneself with them, which indicates that they are not suspected of bloodshed? Rather, it is prohibited to sell these items to Samaritans because they will come to sell them to a gentile. According to this reasoning, it should likewise be prohibited to sell a donkey to a Jew who is suspected of selling animals to gentiles. And if you would say that there is a difference between a Jew and a Samaritan, as a Samaritan will likely not repent and will sell to a gentile, whereas a Jew will likely repent and not sell these items, this reasoning is incorrect. But doesn’t Rav Naḥman say explicitly that Rabba bar Avuh says: Just as the Sages said that it is prohibited to sell to a gentile, so too it is prohibited to sell to a Jew who is suspected of selling to a gentile? When Rabba heard this and realized that Abaye was correct, he ran three parasangs after the buyer who purchased his donkey to revoke the sale, as the Jew was suspected of selling to gentiles; and some say that he ran one parasang through sand. But he did not succeed in overtaking him. 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.

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.