"Mama," he replies, "in America, nobody wears a beard."
"But at least you keep the Sabbath?"
"Mama, business is business. In America, everybody works on the Sabbath."
"But kosher food you still eat?"
"Mama, in America, it is very difficult to keep kosher."
The old lady ponders this information and then leans over and whispers in his ear, "Isaac, show me that--you're still circumcised?"