Give it a rest
Definition 1 of 1
Pro Tip 1/3Casual Expression
Used in informal situations among friends or family, not in professional settings. 
After complaining all day, I told my friend to give it a rest.
Pro Tip 2/3Potential Annoyance
Implies the listener or others are irritated by the subject or action being addressed. 
You keep asking about my ex, can you give it a rest?
Pro Tip 3/3Avoid Overuse
Use it sparingly to prevent sounding rude or dismissive if overused. 
I know you're upset, but give it a rest now, please.