'Sworn' in the Bible

Therefore I have sworn to the house of Eli, that the iniquity of Eli's house shall not be removed with sacrifice nor offering forever."

Jonathan said to David, "Go in peace, because we have both sworn in the name of Yahweh, saying, 'Yahweh shall be between me and you, and between my seed and your seed, forever.'" He arose and departed; and Jonathan went into the city.