'Vain words' in the Bible

Let more work be laid upon the men, and let them labor in it. And do not let them regard vain words.

But when you pray, do not babble vain words, as the nations. For they think that in their much speaking they shall be heard.

Let no man deceive you with vain words, for because of these things the wrath of God comes upon the children of disobedience.