Generally speaking, as we learned in Masechet Makkot, punishments meted out by Jewish courts were given only when the perpetrator committed an act forbidden by the Torah. If, however, the person neglected to perform a positive commandment, the Torah does not punish him in any way (although the Sages enacted punishments whose aim was to encourage performance of positive mitzvot). Similarly, negative commandments that do not involve forbidden actions – referred to in the Gemara as lav she-ein bo ma’aseh – are not punishable, since there was no forbidden action that was done.
Where do false oaths fit in? Since an oath usually involves speech with no action, is it considered to be a lav she-ein bo ma’aseh, or, perhaps, the act of speaking is considered significant?
On today’s daf (=page) Rabbi Yehudah is brought quoting Rabbi Yossi ha-Galili as teaching that there are three exceptions to the rule of no punishment for a lav she-ein bo ma’aseh. The three exceptions are nishba (taking a false oath), meimar (announcing one’s intent to switch one consecrated animal for another) u’mekalel et haveiro ba-shem(cursing one’s fellow while invoking the name of God).
It appears, somewhat counter-intuitively, that the Gemara does not consider speech to be an action, yet nevertheless, these types of speech are presented by the Torah as exceptions to the rule and malkot (lashes) will be given to someone who transgresses them.
In explaining the unique punishment of malkot for a false oath, Rabbi Yohanan quotes Rabbi Shimon bar Yohai as teaching that the source is the passage in the Ten Commandments where we find that God will offer no atonement for someone who takes his name in vain (see Shemot 20:6). From this they infer that while there is no heavenly atonement offered, atonement can be made by means of punishment meted out by the courts.
Tosafot point out that there are other examples of speech for which punishment is given, e.g. eidim zomemin (witnesses that are found to be testifying falsely since they were not at the scene that they describe) or motzi shem ra (someone who falsely accuses his wife of premarital infidelity), and explain that in those cases the Torah itself clearly states the punishments associated with those statements.