- Swearing that something is not what everyone knows it to be (e.g. that a stone pillar is made of gold)
- Swearing about something that is impossible (e.g. that he saw a camel flying in the air).
It is interesting to note that although a person who takes such a shevuat shav will be liable to bring a sacrifice, had he taken a neder such as this, he would not be held responsible in any way, as we would assume that he is simply exaggerating, or speaking in a manner that is not serious.
Why is there a difference between shevuot and nedarim with regard to these types of statements?
One approach suggested by Tosafot is that when discussing nedarim, we are inclined to pay attention to the way people ordinarily speak. Since we know that people exaggerate, we will assume that that was his intention. Shevuot, on the other hand, which include invoking the name of God, are treated in a more serious manner. Rabbeinu Ḥananel adds that this type of oath is the one that is specifically referred to in the Ten Commandments (see 20:6).
The Talmud Yerushalmi quotes two different baraitot regarding these issues – one of them appears to hold the individual liable for making such a shevuat shav, while the other one appears to free him of any responsibility. The Yerushalmi distinguishes between cases by saying that it depends whether the person was ma’amid – if he “stands” – or not. This is explained as follows: If a person says a wild exaggeration and is challenged, if he recants then we understand that it was merely an exaggeration and he is not liable. If, however, he insists that what he said is true, and swears that it is so, then he is held liable for having taken a shevuat shav.