'Took an Oath' in the Bible

Then David {took an oath} again and said, "Your father knows very well that I have found favor in your eyes, and he thought, 'Do not let Jonathan know this, lest he worry.' But {as Yahweh lives} and {as your soul lives}, surely [there is] merely a step between me and death!"

And they took an oath to Yahweh with a great voice, with shouting, with trumpets, and with horns.