knock it off

[knock it off] {v. phr.}, {slang}, {informal} 1. To stop talkingabout something considered not appropriate or nonsensical by thelistener. - Used frequently as an imperative.

Come on, Joe, knockit off, you're not making any sense at all!

2. To cease doingsomething; to quit. - Heavily favored in the imperative.

Come onboys, knock it off, you're breaking the furniture in my room!