'Knew' in the Bible

So I stood over him, and put him to death, for I knew that he would not live after his fall; and I took the crown that was upon his head, and the bracelet that was on his arm, and have brought them hither to my lord.

And it came to pass as Joab watched the city, that he assigned Urijah to a place where he knew that the valiant men were.

And with Absalom went two hundred men out of Jerusalem, that were invited; and they went in their simplicity, and they knew nothing.

And the king said, Is it well with the young man Absalom? And Ahimaaz said, I saw a great tumult when Joab sent the king's servant, and me thy servant; but I knew not what it was.

And thou hast delivered me from the strivings of my people, Thou hast kept me to be head of the nations: A people I knew not doth serve me: