don't make a threat you cannot carry out

don't make a threat you cannot carry out

Don't threaten to do something or punish someone unless you are both willing and able to do it. A: "If they keep grumbling like that, I'll just tell them that their pay will start getting docked." B: "Careful, Jim. You know that half the staff would walk out if you did that, and they know that too. Don't make a threat you can't carry out."
See also: cannot, carry, make, out, threat