Origin of Phrases - B
Blowing smoke
Meaning: To be boasting without being able to back it up, talking about action without intent to follow through.
Example: Do you really want to buy this car or are you just blowing smoke?
Origin: Magicians often use smoke in their performance to obscure your view and conceal a bit of trickery. A person who is "blowing smoke" is tricking you and attempting to cover it up.