Exodus 6:7 (KJV)

And God spake unto Moses, and said unto him, I am the LORD:

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.

And I have also established my covenant with them, to give them the land of Canaan, the land of their pilgrimage, wherein they were strangers.

And I have also heard the groaning of the children of Israel, whom the Egyptians keep in bondage; and I have remembered my covenant.

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:

And I will bring you in unto the land, concerning the which I did swear to give it to Abraham, to Isaac, and to Jacob; and I will give it you for an heritage: I am the LORD.

And Moses spake so unto the children of Israel: but they hearkened not unto Moses for anguish of spirit, and for cruel bondage.

And the LORD spake unto Moses, saying,

Go in, speak unto Pharaoh king of Egypt, that he let the children of Israel go out of his land.

And Moses spake before the LORD, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips?