What does Black Hand Slap mean?

Black Hand Slap meaning in Urban Dictionary

using somebody because of the collar/turtle neck and slaping all of them to and fro because of the top and under sides of your hand and saying saying bitch butt nigga over and oversorta such as the back hand punch, however with what nigga, bitch, and butt in just about any kind of order, but must include the word nigga, i.e. the "black" hand punch