 Heston says that he was the one who suggested that Wyler cast Martha Scott (who had played the mother of Heston's Moses in "The Ten Commandments", and with whom he'd worked on Broadway) as Miriam.Scott was hired on July 17, 1958.Cathy O'Donnell was Wyler's sister-in-law, and although her career was in decline ("Ben-Hur" would be her last screen performance) Wyler cast her as Tirzah.