Do not swear in vain.
“Do not take the name of God in vain” Shmos 20:7
A vain oath is divided into 4 categories.
If he swears to a change in something known, for example, if he swears regarding a man that he is a woman or that a stone is gold.
If he swears for no purpose, for example, he swears that a stone is a stone
If he swears not to observe a Mitzvah
If he swears to do something that is impossible to fulfil, for example that he will not sleep for 3 consecutive days or eat any food for 7 consecutive days.
Regarding these oaths if he swore intentionally he is liable to receive lashes.
If done accidently he is free from punishment.
Saying a benediction needlessly or uttering the name of Heaven for no purpose is a violation of the prohibition “do not take the name of God in vain”
This applies in all places at all times for men and women.