'Empty' in the Bible

Then he said, Go, borrow thee vessels abroad of all thy neighbours, even empty vessels; borrow not a few.

He replied, "No, let the Lord help you. How can I help you? The threshing floor and winepress are empty."

They rejected His statutes and His covenant which He made with their fathers, as well as His warnings that he gave them. And they followed vanity [that is, false gods, idols] and became vain (empty-headed). They followed the [pagan practices of the] nations which surrounded them, although the Lord had commanded that they were not to do as they did.

""Why are you so confident? You're saying but they're only empty words "I have enough advice and resources to conduct warfare!'