Genesis 15:4-6 NIV

[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.” [6] Abram believed the LORD, and he credited it to him as righteousness.