'Swear' in the Bible

Go and get thee in unto king David, and say unto him, Didst not thou, my lord, O king, swear unto thy handmaid, saying, Assuredly Solomon thy son shall reign after me, and he shall sit upon my throne? why then doth Adonijah reign?

And it was told Solomon, saying, Behold, Adonijah feareth king Solomon; for, lo, he hath laid hold on the horns of the altar, saying, Let king Solomon swear unto me first that he will not slay his servant with the sword.

If a man sin against his neighbor, and an oath be laid upon him to cause him to swear, and he come and'swear before thine altar in this house;