The 61st prohibition is that we are forbidden from violating the type of oath called a sh'vuas bitui.1

The source of this commandment is G‑d's statement,2 "Do not swear falsely in My name."

A sh'vuas bitui is an oath to do something (or to refrain from doing something) that the Torah does not prohibit (or require).3 We are required to fulfill such an oath4 and are prohibited from violating it by virtue of His statement, "Do not swear falsely in My name."

Our Sages said in tractate Sh'vuos,5

"What is a sh'vuas sheker?6 When one swears to change [the truth."]7

The Gemara amends this; "It should read, 'When one swears and changes,'" i.e., swearing to do something, and then doing the opposite of the oath.8

In the third chapter of Sh'vuos, as well as in tractate T'murah,9 it is explained that a sh'vuas sheker is the non-fulfillment of a sh'vuas bitui. There our Sages say, "What kind of sh'vuas sheker is meant?" This refers to the Gemara's previous statement regarding a sh'vuas sheker where no action was performed [and the punishment is nevertheless lashes]. "If you say [it refers to a case where the person swore,] 'I will not eat,' and the person ate, then an action was performed. [Therefore, that case could not be what the Gemara was referring to.] If you say [it refers to a case where the person swore,] 'I will eat,' and the person didn't eat, is he punished by lashes? [This cannot be, for] it says explicitly..." [that there are no lashes in such a case.]10

One who transgresses this prohibition intentionally is punished by lashes. If it was done unintentionally, he must bring an offering of adjustable value, as explained in positive commandment 72. The source for this is the statement in the third chapter of Sh'vuos,11 "This is a sh'vuas bitui, which, if one violates intentionally, is punished by lashes, and if unintentionally, must bring an offering of adjustable value." The details of this mitzvah are explained there.

You should be aware that when I said that this prohibition is punished by lashes if done intentionally, this does not mean that there is another prohibition for which there is lashes even if done unintentionally. Rather, you should keep in mind that every time I say that a certain prohibition is punishable by lashes (whether it was said in a previous mitzvah or in a following mitzvah), this is only when done intentionally, in the presence of witnesses, and after being warned — the conditions regarding the witnesses and the warning being found in tractate Sanhedrin.12

If, however, the transgression was done unintentionally, or if the person was forced, or if he made an error, he is not punished by lashes or kares, and certainly not by execution. You should keep this in mind, for it applies to all the mitzvos.

In those few mitzvos where we say explicitly that the punishment is lashes or execution when done intentionally, this is said in order to distinguish from the case where an unintentional violation necessitates a sacrifice. [This must be said] because not every unintentional prohibition entails a sacrifice.13

But every case of punishment by kares, lashes, or execution is carried out only where there were witnesses and a warning. You should keep this principle in mind so that it will not be necessary to repeat it.