Genesis 15:4-6

4Then 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.”

5He 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 Or seed be.”

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