Negative Commandment #29
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
29. It is a negative commandment "Do not swear in vain"
As it states in Shemos (Exodus) 20:7, "You shall not take the name of G-d in vain." A swear made in vain can be divided into four categories: 1) If one swears to change something that is known, like swear that a man is a woman, or a rock is gold. 2) If one swears with no purpose, like swearing that a rock is a rock. 3) If one swears not to perform a commandment. 4) If one swears to do something that is impossible, like not to sleep for three days in a row or not to taste food for seven days in a row. On all of these swearings: if he swore knowingly, he is to receive whipping. If he swore accidentally, he receives no penalty. If a person says a blessing that is not required or states G-d's Name for no purpose, he transgresses this commandment.
This applies in all places and at all times, for men and for women.