Genesis 15:4-8

4Then the Lord said to him, “No, your servant will not be your heir, for you will have a son of your own who will be your heir.”

5Then the Lord took Abram outside and said to him, “Look up into the sky and count the stars if you can. That’s how many descendants you will have!”

6And Abram believed the Lord, and the Lord counted him as righteous because of his faith.

7Then the Lord told him, “I am the Lord who brought you out of Ur of the Chaldeans to give you this land as your possession.”

8But Abram replied, “O Sovereign Lord, how can I be sure that I will actually possess it?”