'Certainty' in the Bible

know for a certainty that Yahweh your God will no longer drive these nations from out of your sight; but they shall be a snare and a trap to you, a scourge in your sides, and thorns in your eyes, until you perish from off this good land which Yahweh your God has given you.

See therefore, and take knowledge of all the lurking places where he hides himself, and come again to me with certainty, and I will go with you: and it shall happen, if he is in the land, that I will search him out among all the thousands of Judah."

The king answered, I know of a certainty that you would gain time, because you see the thing is gone from me.

that you might know the certainty concerning the things in which you were instructed.