2,640. Oaths of Exaggeration

Hilchos Shevuos 3:5

One isn’t liable for oaths of exaggeration or for unintentional oaths. An example of an oath of exaggeration is if someone saw an immense army and a tall wall, and he took an oath that the soldiers of that king are as numerous as the Jews who left Egypt and that the wall of that city is as high as the heavens. One is exempt in such a case because he didn’t have the intention in his heart that this was the actual measure of the thing. Rather, his intent was strictly for descriptive purposes.

Hilchos Shevuos 3:6

An unintentional oath, as far as an oath of deposit and an oath of testimony, refers to a case in which one forgot about the deposit or the testimony. Such a person is wholly exempt, as has already been discussed. As far as an oath in vain, it refers to a case such as one who took an oath not to wear tefillin, unaware that tefillin are a mitzvah. For a false oath, it refers to a case where someone took an oath that he didn’t eat but he later remembered that he did, or he took an oath not to eat but he forgot and ate, or he took an oath not to please his wife because she took his wallet or beat their child and he later found out that she didn’t take the wallet or beat the child. The same is true in all comparable cases.