'As Your Soul Lives' in the Bible

Hannah said, “Oh, my lord! As [surely as] your soul lives, my lord, I am the woman who stood beside you here, praying to the Lord.

When Saul saw David going out against the Philistine, he said to Abner the captain of the army, “Abner, whose son is this young man?” And Abner answered, “By your life, O king, I do not know.”

But David vowed again, saying “Your father certainly knows that I have found favor in your sight, and he has said, ‘Do not let Jonathan know this, or he will be worried.’ But truly as the Lord lives and as your soul lives, there is hardly a step between me and death.”

So now, my lord, as the Lord lives, and as your soul lives, since the Lord has prevented you from shedding blood, and from avenging yourself by your own hand, now then let your enemies and those who seek to do evil to my lord, be as [self-destructive as] Nabal.