'As You Live' in the Bible

“Please, my lord,” she said, “as sure as you live, my lord, I am the woman who stood here beside you praying to the Lord.

When Saul had seen David going out to confront the Philistine, he asked Abner the commander of the army, “Whose son is this youth, Abner?”“My king, as surely as you live, I don’t know,” Abner replied.