save one's breath(redirected from save your breath to cool your porridge (or broth))
save (one's) breath
To spare the effort of saying something, doing something, or making an appeal that will be futile. Save your breath, Tom. There's no way they'll agree to the deal. I was going to complain to the phone company about the extra charges, but I decided to save my breath.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
save one's breath
Refrain from arguing about a lost cause, as in You can save your breath; I'm not going to change my mind. This term was also put as save your breath to cool your porridge (or broth), that is, by not blowing on the too hot liquid. The idea of not expending one's breath to say something another person doesn't want to hear dates from the early 1700s.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.