Genesis 15:6

3 And Abram said, You have given me no child, and a servant in my house will get the heritage.

4 Then said the Lord, This man will not get the heritage, but a son of your body will have your property after you.

5 And he took him out into the open air, and said to him, Let your eyes be lifted to heaven, and see if the stars may be numbered; even so will your seed be.

6 And he had faith in the Lord, and it was put to his account as righteousness.

7 And he said to him, I am the Lord, who took you from Ur of the Chaldees, to give you this land for your heritage.

8 And he said, O Lord God, how may I be certain that it will be mine?

9 And he said, Take a young cow of three years old, and a she-goat of three years old, and a sheep of three years old, and a dove and a young pigeon.