'Sworn' in the Bible

Therefore I have sworn to the house of Eli that the iniquity of Eli’s house shall not be atoned for by sacrifice or offering forever.”

Jonathan said to David, “Go in safety, inasmuch as we have sworn to each other in the name of the Lord, saying, ‘The Lord will be between me and you, and between my descendants and your descendants forever.’” Then he rose and departed, while Jonathan went into the city.