Genesis 15:2-5 NIV

[2] But Abram said, “Sovereign Lord, what can you give me since I remain childless and the one who will inherit my estate is Eliezer of Damascus?” [3] And Abram said, “You have given me no children; so a servant in my household will be my heir.” [4] Then the word of the LORD came to him: “This man will not be your heir, but a son who is your own flesh and blood will be your heir.” [5] He took him outside and said, “Look up at the sky and count the stars—if indeed you can count them.” Then he said to him, “So shall your offspring be.”