Shavuos 21 - 27
The Oath and the "Man"
If a man takes a false oath as a result of a lack of awareness the Torah requires him to bring a sin-offering as an atonement. The Torah's stress on the word man, says the Talmud, is to indicate that this responsibility applies only to when he was entirely a man at the time of the oath, completely aware of the circumstances.
The following case is cited as an example of where no sacrifice is required because the one who took the oath did so in circumstances beyond his control.
Rabbi Kahana and Rabbi Assi were both disciples of the Sage Rav. When they left Rav's presence they had a dispute as to what he had taught them. Each one of them took an oath that Rav had taught what he claimed to have heard from him. When they returned to Rav he informed them which one was right. His disappointed colleague turned to Rav and asked: "Does this mean that I was guilty of taking a false oath?"
"No," Rav reassured him, "for your memory deceived you into believing that I had made the statement you reported. You were therefore not considered the man who is responsible for seeking atonement for a false oath taken because of a lack of awareness."
In similar fashion, if one takes an oath that he ate something because that is what his memory told him and it turns out that he did not eat it he will not have to bring a sacrifice. But if he says, "I know I did not eat it and that it is forbidden to take an oath that I ate it but I am not aware of whether there is an obligation to bring a sacrifice for such a violation" - this is a case when he is considered a man who sinned with full knowledge of the circumstances but as a result of a lack of awareness of the gravity of the sin, and such an oath-taker must bring a sin-offering as an atonement.
- Shavuos 26a-b
When Words Count as Action
"You shall not take the Name of Hashem your G-d in vain,"
reads the Third commandment,
"for Hashem will not absolve one who takes His Name in vain."
The stress on Hashem not absolving one who takes a false oath leads Rabbi Shimon bar Yochai to deduce that only the Heavenly Court offers no absolution, while the human court does offer him absolution through the atonement of lashes. This leads to the conclusion that taking a false oath is punishable by lashes, an exception to the general rule that lashes are never given when there is no action beyond mere speech.
- Shavuos 21a