'Certainly' in the Bible

"I am about to send my messenger, who will clear the way before me. Indeed, the Lord you are seeking will suddenly come to his temple, and the messenger of the covenant, whom you long for, is certainly coming," says the Lord who rules over all.

"The coming day is certainly going to burn like a furnace. All the arrogant and all who practice evil will be stubble the coming day will set them on fire," says the LORD of the Heavenly Armies, "so that it will leave them neither root nor branch.