The tri-question (one theme) is this:
1. on what basis were the Israelites supposed to believe in Moses when they were still in Egypt? (way before Sinai)
2. on what basis was pharaoh supposed to believe that Moses is a prophet of God and obey Moses? what was the proof that Moses was a prophet of God?
when Moses first came up to the Israelites and pharaoh, what did he say or do to convince them that God talked to him and that he's a prophet of God?
3. how did Moses himself know that it was really God the Creator of heavens and earth talking to him from the burning bush and commanding him to do thing. how did he know he was really a prophet of God?
M. Gracias.
JD










