"Tell Bill I said to have a Coke and a smile and to shut the F up." - Richard Pryor to Eddie Murphy.
Besides it was Richard Pryor who said "I've been to penitentiaries, and all I can say is, 'Thank God, we've got penitentiaries.'"
We'll never know the real truth, but Cosby later said that he never chastised Eddie about "filth," rather he chastised Eddie about his attitude towards the audience when he was "off" one night. Cosby said Eddie went off on the audience saying something like, "screw you people...I make millions of dollars...blah blah blah."
Anyway, that was Cosby's version.