hi! I'll leave someone else to comment on the language used in the film, but as for your other questions, there have been a few related posts

General discussions on "how do we know?"

• How do we know what ancient languages sounded like?

• How do historians know if they are pronouncing ancient names correctly?

• How do we know what ancient Egyptian words sounded like?

How did ancient Egyptian sound?

• What did the Ancient Egyptian language sound like?

• What did the language spoken by the Ancient Egyptians sound like?

• What did the Ancient Egyptian's spoken language sound like?

• Do we know what ancient languages actually sounded like?

He spoke some Hebrew too. I can tell you he used a modern Israeli accent.