'As You Live' in the Bible

Now as Saul watched David going out to fight the Philistine, he asked Abner, the general in command of the army, "Whose son is this young man, Abner?" Abner replied, "As surely as you live, O king, I don't know."

"Now, my lord, as surely as the Lord lives and as surely as you live, it is the Lord who has kept you from shedding blood and taking matters into your own hands. Now may your enemies and those who seek to harm my lord be like Nabal.