the rough edge of your tongue

the rough edge of (one's) tongue

A harsh scolding or rebuke; a verbal lashing. The teacher gave us the rough edge of her tongue after she caught us reading comics in the back of class. I know you feel they deserve the rough edge of your tongue at times, but you need to show some restraint or you're going to lose their respect.
See also: edge, of, rough, tongue
Farlex Dictionary of Idioms.

the rough edge (or side) of your tongue

a scolding.
See also: edge, of, rough, tongue
Farlex Partner Idioms Dictionary
See also:
  • the rough edge of (one's) tongue
  • the rough side of (one's) tongue
  • catch it in the neck
  • give (one) a tongue-lashing
  • give someone a tongue-lashing
  • lashing
  • tongue-lashing
  • hold one's tongue, to
  • get it in the neck
  • take it in the neck