'Sware' in the Bible

And Saul hearkened unto the voice of Jonathan: and Saul sware, As Jehovah liveth, he shall not be put to death.

And David sware moreover, and said, Thy father knoweth well that I have found favor in thine eyes; and he saith, Let not Jonathan know this, lest he be grieved: but truly as Jehovah liveth, and as thy soul liveth, there is but a step between me and death.

And David sware unto Saul. And Saul went home; but David and his men gat them up unto the stronghold.

And Saul sware to her by Jehovah, saying, As Jehovah liveth, there shall no punishment happen to thee for this thing.