Exodus 6:1-3 NIV
Then the LORD said to Moses, “Now you will see what I will do to Pharaoh: Because of my mighty hand he will let them go; because of my mighty hand he will drive them out of his country.”
God also said to Moses, “I am the LORD. I appeared to Abraham, to Isaac and to Jacob as God Almighty, but by my name the LORD I did not make myself fully known to them.
NIV: New International Version