"Talk to the hand" (or "tell it to the hand") is an English language slang phrase associated with the 1990s. It's a contemptuous and urbanized way of saying that no one is listening, and is often elongated to a phrase such as "Talk to the hand, because the ear's not listening" or "Talk to the hand, (be)cause the face don't understand" or "Talk to the hand, (be)cause the face don't give a damn."
It is usually accompanied by the gesture of extending one arm toward the other person, with the palm of that hand facing the person being insulted.