Swearing Falsely: Forbidden
Source: TTT
Leviticus 19:12
You must not swear falsely by My name and so profane the name of your God. I am the LORD.
Numbers 30:2
If a man makes a vow to the LORD or swears an oath to obligate himself by a pledge, he must not break his word; he must do everything he has promised.
Matthew 5:33
Again, you have heard that it was said to the ancients, ‘Do not break your oath, but fulfill your vows to the Lord.’