No, sorry, I don't have the link, but I edited it; it was originally a more complex joke.
Usher: "Don't sit in the front, the pastor is terribly boring."
Lady: "Do you know who I am?"
Usher: "Uhh...no."
Lady: "I'm the pastor's mother! "
Usher: "Do you know who I am?"
Lady: "No, I don't."
Usher: "Thank God! "