Genesis 15:4-8

4Then the word of the LORD came to Abram, saying, “This one will not be your heir, but one who comes from your own body will be your heir.” 5And the LORD took him outside and said, “Now look to the heavens and count the stars, if you are able.” Then He told him, “So shall your offspring be.”1

6Abram believed the LORD, and it was credited to him as righteousness.2

7The LORD also told him, “I am the LORD, who brought you out of Ur of the Chaldeans to give you this land to possess.”

8But Abram replied, “Lord GOD, how can I know that I will possess it?”