Genesis 15:7

And He said unto him, I am the Lord that brought thee out of Ur of the Chaldees, to give thee this land to inherit it. In preparing to give Abram a special sign of the covenant's consummation and to assure him of the fact that his descendants would be the possessors of the land of Canaan, the Lord introduces Himself as He whose conduct in the past is a guarantee of His faithfulness in the future.