Genesis 15:1-4

After these things the word of the LORD came to Abram in a vision, saying, “Do not be afraid, Abram, I am your shield; Your reward [for obedience] shall be very great.” Abram said, “Lord GOD, what reward will You give me, since I am [leaving this world] childless, and he who will be the owner and heir of my house is this [servant] Eliezer from Damascus?” And Abram continued, “Since You have given no child to me, one (a servant) born in my house is my heir.” Then behold, the word of the LORD came to him, saying, “This man [Eliezer] will not be your heir but he who shall come from your own body shall be your heir.”