Genesis 15:1-4

After this, the word of the LORD came to Abram in a vision: “Do not be afraid, Abram. I am your shield, your very great reward.” 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?” And Abram said, “You have given me no children; so a servant in my household will be my heir.” 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.”