The statement talk to the hand is offensive, yet I remember my delighted surprise when I first heard someone say it to me. I found the expression quite clever as I got dissed (rejected) in calculus class. When some one says talk to the hand, he or she extends out a hand towards the person being dissed. As the reject gazes at the offender's palm, the offender turns his or her face away, exclaiming "talk to the hand." The expression means that some one does not want to hear what you have to say. What you have to say is so unimportant that you can only say it to the person's hand, while the person turns away. The hand placement also works on a symbolic level. When cops want to stop traffic, they make the same gesture with their hands. The gesture means stop. So at once the offender simbolically says stop, turns away, and yet leaves the reject the pathetic option of talking to a hand.