Swearing an oath
At Leviticus 5:1, we read:
‘And if a person sins by witnessing, seeing, or knowing of someone that has sworn an oath [of vengeance] against another and doesn’t report it, he is responsible for his sin.’
Unfortunately, many Bibles translate the word used here, horkismou, as just swearing.
Yet in American English, that generally implies using a profanity. However, horkismou refers to swearing an oath (in vengeance), not necessarily to the use of profanities.
So although this verse is often used by religious groups to condemn the use of profanities, this isn’t what the word implies.
To better understand the seriousness involved in cursing another in the Name of God, see the translator note, Dedicated to Destruction.