Exodus 6:1-3

Then the LORD said to Moses, “Now you shall see what I will do to Pharaoh. For with a strong hand he will let them go, and with a strong hand he will drive them out of his land.” And God spoke to Moses and said to him: “I am the LORD. I appeared to Abraham, to Isaac, and to Jacob, as God Almighty, but by My name LORD I was not known to them.