'Knew' in the Bible

So I stood over him and killed him because I knew that after he had fallen he couldn’t survive. I took the crown that was on his head and the armband that was on his arm, and I’ve brought them here to my lord.”

And when Joab was come out from David, he sent messengers after Abner, which brought him again from the well of Sirah: but David knew it not.

Then David knew that the Lord had established him as king over Israel and had exalted his kingdom for the sake of His people Israel.

And it came to pass, when Joab observed the city, that he assigned Uriah unto a place where he knew that valiant men were.

And if so be that the king's wrath arise, and he say unto thee, Wherefore approached ye so nigh unto the city when ye did fight? knew ye not that they would shoot from the wall?

Meanwhile, Zeruiah's son Joab knew that the king's attention was focused on Absalom,

And with Absalom went two hundred men out of Jerusalem, that were called; and they went in their simplicity, and they knew not any thing.

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

Thou also hast delivered me from the strivings of my people, thou hast kept me to be head of the heathen: a people which I knew not shall serve me.