'Certain' in the Bible

David answered Ahimelech the priest, “The king gave me a mission, but he told me, ‘Don’t let anyone know anything about the mission I’m sending you on or what I have ordered you to do.’ I have stationed my young men at a certain place.

“Now I know for certain you will be king, and the kingdom of Israel will be established in your hand.

Now consider carefully what you must do, because there is certain to be trouble for our master and his entire family. He is such a worthless fool nobody can talk to him!”

Please forgive your servant’s offense, for the Lord is certain to make a lasting dynasty for my lord because he fights the Lord’s battles. Throughout your life, may evil not be found in you.

So David sent out spies and knew for certain that Saul had come.