'Swear' in the Bible

Neither should you swear by your head, because you cannot make a single hair white or black.

Then he started to curse and to swear with an oath, “I do not know the man!” Immediately a rooster crowed,

Then he started to curse and to swear with an oath, “I don’t know this man you’re talking about!”

And who did He swear to that they would not enter His rest, if not those who disobeyed?

For when God made a promise to Abraham, since He had no one greater to swear by, He swore by Himself:

For men swear by something greater than themselves, and for them a confirming oath ends every dispute.

Now above all, my brothers, do not swear, either by heaven or by earth or with any other oath. Your “yes” must be “yes,” and your “no” must be “no,” so that you won’t fall under judgment.