Exodus 6

Exodus 6:1-3 (KJV)
1 Then the Lord said unto Moses, Now shalt thou see what I will do to Pharaoh: for with a strong hand shall he let them go, and with a strong hand shall he drive them out of his land.
2 And God spake unto Moses, and said unto him, I am the Lord:
3 And I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of God Almighty, but by my name Jehovah was I not known to them.

Exodus 6:6,7 (KJV)
6 Wherefore say unto the children of Israel, I am the Lord, and I will bring you out from under the burdens of the Egyptians, and I will rid you out of their bondage, and I will redeem you with a stretched out arm, and with great judgments:
7 And I will take you to me for a people, and I will be to you a God: and ye shall know that I am the Lord your God, which bringeth you out from under the burdens of the Egyptians.