Audrey Hepburn was originally slated for the role of "Nefretiri". Cecil B. DeMille reluctantly decided to pass on her after it was judged that she was too "slender" (i.e., flat-chested). Anne Baxter, who was eventually cast in the role, had originally been a contender for the role of "Sephora."
Julia Faye: Elisheba, Aaron's wife, was also in the 1923 version of The Ten Commandments, where she played the Pharaoh's wife.
Charlton Heston personally requested to Cecil B. DeMille to let him be the voice of God, at the scene of the Burning Bush, and DeMille agreed.
Charlton Heston was chosen for the role of Moses by Cecil B. DeMille because he bore a resemblance to Michelangelo's statue of Moses in Rome. Heston later played Michelangelo in The Agony and the Ecstasy.
Cecil B. DeMille suffered a heart attack during the production after climbing 130 feet to check a faulty camera perched on one of the giant gates used during the exodus sequence, as it was occurring. He took two of days off and then, against his doctor's orders, returned to work to complete the film.
Cecil B. DeMille's original choice for Moses was William Boyd, best known as "Hopalong Cassidy". Boyd turned down the role, fearing his "Hopalong Cassidy" popularity, would hurt the movie's fame, deeply.
H.B. Warner: was "Amminadab", an old Israeli man about to die in the desert, during the Exodus sequence. This was his last film appearance.
Martha Scott, who played Charlton Heston's mother, in his two Biblical epics, The Ten Commandments and Ben-Hur, was only ten years older than her on-screen son.
Gloria Swanson was originally cast as Memnet, but she was then having difficulties getting a backer for a musical stage version of Sunset Blvd. so she had to depart from the project (The musical eventually had to be abandoned in the early 1960s, even after a cast album was recorded during out-of-town tryouts).
Babette Bain, Fraser Clarke Heston: Babette Bain was Little Miriam, while Fraser Clarke Heston, son of Charlton Heston was Moses, as an infant.
Mike Sill: uncredited former Mr. America was one of the persons helping to carry the Idol of the Golden Calf.
According to Charlton Heston's autobiography, the filming of the orgy scenes was so grueling, it prompted one female extra to exclaim, "Who do I have to f**k to get OUT of this movie?"
According to author Simon Louvish in his Cecil B. DeMille biography 'Cecil B. DeMille: A Life in Art', the role of Moses was originally intended for (and first offered to) actor William Boyd, who had also played the coveted cameo role of Simon the Cyrene in DeMille's silent film The King of Kings. Boyd was obliged to decline the role in "The Ten Commandments" due to his commitment to the production of his enormously popular Hopalong Cassidy television series, which was scheduled to continue production simultaneous to the filming of the DeMille picture. DeMille was persuaded to hire actor Charlton Heston for the role after being presented with a statuette likeness of Moses by the Israeli government, and noting the Heston's resemblance to the statuette.
According to Hollywood lore, while filming the orgy sequence which precedes Moses' descent from Mount Horeb with the two stone tablets of the Ten Commandments engraved, Cecil B. DeMille was perched on top of a ladder delivering his customarily long-winded directions through a megaphone to the hundreds of extras involved in the scene. After droning on to the extras for several minutes, DeMille was distracted by one young woman who was persistently talking to the woman standing next to her. DeMille stopped his speech and addressed everyone's attention to the young woman. "Here," DeMille said, "We have a young woman whose conversation with her friend is apparently more important than listening to her instructions from her director while we are all engaged in making motion picture history. Perhaps the young woman would care to enlighten us all, and tell us what the devil is so important that it cannot wait until after we make this shot." After a moment, of silence and temporary fright, she spoke up and boldly confessed, "I was just saying to my friend, 'I wonder when that bald-headed old fart is gonna call 'Lunch!'" DeMille stared at her for a moment, paused, then lifted his megaphone, and then shouted, "Lunch!"
Actress, Nina Foch, had role of Bithiah, was actually one year younger than Charlton Heston, her 30-year on-screen son, Moses.
Although by 1956 virtually all widescreen epics were being filmed with stereophonic sound, The Ten Commandments was not filmed in stereo. The sound was remixed to stereo for later releases.
Animation was employed to create the hail as it was falling from the sky in the background, but popcorn that had been spray-painted white fell as "hail" onto the pavilion of Rameses' palace. It was light so it could not hurt the actors, it bounced like real hail; and it could be swept up and used again for additional takes of the scene. The fire that burned from the hail was created by animation.
Another plague was filmed but was not used. According to the commentary on the 50th Anniversary DVD, in 2006. This was the plague of frogs leaving the muddied Nile, coming up onto land, frightening and chasing Nefretiri and other Egyptians through their chambers of the palace. Cecil B. DeMille felt that the scene was not frightening enough, and could even be considered too humorous; thus, he omitted it from its final filming and completion, just before he and all other directors and production staff completed it and it would start being seen, in theaters, in 1956.
Apart from Charlton Heston, almost no one in the leading and major supporting parts were actually Paramount contract players. By 1954, when the film began shooting, most of the studios had dropped their contract players due to sweeping changes in the industry and competition with television.
As a publicity stunt, Cecil B. DeMille had public displays and monuments of the Ten Commandments erected around the country. Known as decalogues, most of them were placed in, on or near government buildings.