What is a vain oath? One [who] swears to contradict what is known to man: [For example,] he said concerning a pillar of stone that it is of gold, concerning a man that he is a woman, or concerning a woman that she is a man. One [who] swears concerning some-thing that is impossible: [for example,] “If I did not see a camel flying through the air,” or, “If I did not see a snake like the beam of an olive press.” One [who] said to witnesses, “Come and testify for me,” [and they replied,] “We swear that we will not testify for you.” One [who] swears to annul a mitzvah; [for example,] not to make a succah, not to take a lulav, or not to put on tefillin. These are the vain oaths for which one is liable to [a penalty of] lashes for their willful transgression, and for whose inadvertent transgression one is exempt.