Play on of LL Cool J's famous hit "Momma said knock you out". Derived by a boy and his father in Rochester NY, who saw and angry black man walking with a bag. Can be used as a catchphrase before fucking someone up.
Person 1: What you gonna do?
Person 2: Momma said fuck you up!
Person 1: Oh shazbot!
Person 2 proceeds to fuck up Person 1 and take his shit