Genesis 15:6

3 And Abram said, Behold, to me thou hast given no seed: and, lo, one born in my house is mine heir.

4 And, behold, the word of the LORD came unto him, saying, This shall not be thine heir; but he that shall come forth out of thine own bowels shall be thine heir.

5 And he brought him forth abroad, and said, Look now toward heaven, and tell the stars, if thou be able to number them: and he said unto him, So shall thy seed be.

6 And he believed in the LORD; and he counted it to him for righteousness.

7 And he said unto him, I am the LORD that brought thee out of Ur of the Chaldees, to give thee this land to inherit it.

8 And he said, Lord GOD, whereby shall I know that I shall inherit it?

9 And he said unto him, Take me an heifer of three years old, and a she goat of three years old, and a ram of three years old, and a turtledove, and a young pigeon.