'Sure' in the Bible

Now I am sure that the Lord will deliver his chosen king; he will intervene for him from his holy heavenly temple, and display his mighty ability to deliver.

Then make sure you don't speak evil words or use deceptive speech!

For the music director, Jeduthun; a psalm of David. I decided, "I will watch what I say and make sure I do not sin with my tongue. I will put a muzzle over my mouth while in the presence of an evil man."