Jerry Stiller — who famously played George Costanza's dad on "Seinfeld" — says he was always confused about the on-screen family’s heritage.

In a video appearance at the Museum of the Jewish People at Beit Hatfutsot gala at the Mandarin Oriental on Monday, the veteran comic said, "It was never really clear if the Costanzas were Jewish or Italian or what they were. Jason [Alexander, who played George], Estelle [Harris, who played Estelle Costanza] and I were given the name Costanza, which sounds Italian, but there were episodes where I cooked Jewish food and ate knishes and kasha varnishkes in bed."

Stiller added, "When people asked me about this, I would simply say it was because we were a Jewish family in the witness protection program."

A replica of Jerry Seinfeld's apartment is part of the Tel Aviv, Israel, museum's new exhibit on Jewish humor.

"What about the Costanzas' living room? What are we, chopped liver? Oy, serenity now!" Stiller quipped.