"Beat a dead horse"

"Beat a dead horse" means to keep talking about or trying to do something that has already been settled, decided, or is no longer useful. It suggests wasting effort on something that won’t change.

Examples:

There’s no point in arguing about it anymore—you’re just beating a dead horse. (The issue is already decided.)

He keeps bringing up that old mistake. I wish he’d stop beating a dead horse. (Revisiting a past issue unnecessarily.)


It’s often used when someone keeps complaining, debating, or pushing an issue that’s already resolved.