'Take an Oath' in the Bible

Now the men of Israel were hard pressed on that day, because Saul had made the army take an oath, saying, "Cursed be the man who eats [any] food until evening, when I will have avenged myself on my enemies!" So none of the army tasted [any] food.

So they said, "We will restore it and will not request [anything more]. So we will do as you say." Then I called the priests and made them take an oath to do this promise.

So I quarreled with them and cursed them and beat some of their men and pulled out their hair. I made them take an oath by God: "Do not give your daughters to their sons or take their daughters for your sons or for yourselves.