Genesis 15:4-8

4But look, the word of the Lord came to him: “This man will not be your heir, but instead a son who comes from your own body will be your heir.”

5The Lord took him outside and said, “Gaze into the sky and count the stars – if you are able to count them!” Then he said to him, “So will your descendants be.”

6Abram believed the Lord, and the Lord considered his response of faith as proof of genuine loyalty.

7The Lord said to him, “I am the Lord who brought you out from Ur of the Chaldeans to give you this land to possess.”

8But Abram said, “O sovereign Lord, by what can I know that I am to possess it?”