This passage from the Jerusalem Talmud (edited c. 360-370 CE, or as most scholars suggest around 400CE) discusses Mishnah Nedarim 3:4 and other earlier tannaitic material that allows one to deceive Roman officials (Jews or Gentiles) in order to avoid paying taxes or customs. These texts regard Roman tax as illegal and consider collectors of Roman tax and customs as robbers, and thus permit a person to deceive them.

Section (A) aims to explain why a tannaitic tradition (similar to Tosefta Nedarim2:2) will not allow one to vow that the produce belongs to another Jew. In the background of the Talmud’s explanation stands the assumption that one may claim that the produce belongs to another Jew, since this person is a violent man and the collectors will be afraid to approach him. The Talmud maintains that such people often fall from their power, and in such cases the tax officials will approach the violent man, who has fallen from power, and then the previous obligation will be imposed upon the first.

Section (B) cites another tannaitic tradition that allows one to swear (with an oath) to murderers and to Roman officials despite the Torah’s prohibition: “You shall not swear falsely by My name, profaning the name of your God: I am the Lord” [Leviticus 19:12, JPS]. This tradition is mentioned in a context (which I do not cite here because it also contains less relevant issues) that aims to reject the opinion that one may use a vow but not an oath. Both an oath and a vow appear in Numbers 30:2: “When a man makes a vow to the Lord, or swears an oath to bind himself by a pledge, he shall not break his word; he shall do according to all that proceeds out of his mouth” (NRSV). The difference between an oath and a vow is explained in the beginning of Mishnah Nedarim. Usually, in rabbinic texts, a vow (neder in Hebrew) means that one bans himself from certain things by using words that refer to a sacrifice; for example, one would say “this thing is for me as a sacrifice,” usually using the word qonam. In other words, a person declares that certain things are prohibited for him in a similar manner to a sacrifice. In an oath (in Hebrew shvu‘aha) one invokes the name of God (whether explicitly or implied), and, therefore, its consequences are more serious than using a vow. An oath may be used similarly to a vow to ban oneself from certain things in the future, but also in other ways, such as to declare that one will do something in the future, and to give testimony about the past (see the examples in Mishna Shevuot, chapters 3-4). The idea that one is permitted to use an oath in front of customs collectors is supported by the house of Hilell in Mishnah Nedarim 3:4 (b), and is also approved in Tosefta Shevuot2:14: “The one who takes an oath [falsely] in front of Gentiles, customs collectors or robbers (the Greek word lēstēs) is exempt (from punishment)…” (המשביע בפני גוים בפני מוכסין בפני ליסטין פטור).