1 Samuel 20:3 in the King James Version
And David sware moreover, and said, Thy father certainly knoweth that I have found grace in thine eyes; and he saith, Let not Jonathan know this, lest he be grieved: but truly as the LORD liveth, and as thy soul liveth, there is but a step between me and death.
Context
2 He said to him, “Far from it; you will not die. Behold, my father does nothing either great or small, but that he discloses it to me. Why would my father hide this thing from me? It is not so.”
3 David swore moreover, and said, “Your father knows well that I have found favor in your eyes; and he says, ‘Don’t let Jonathan know this, lest he be grieved;’ but truly as the LORD lives, and as your soul lives, there is but a step between me and death.”
4 Then Jonathan said to David, “Whatever your soul desires, I will even do it for you.”