Genesis 15:3-5

New Revised Standard Version, Anglicised Catholic Edition

³ And Abram said, ‘You have given me no offspring, and so a slave born in my house is to be my heir.’ ⁴ But the word of the Lord came to him, ‘This man shall not be your heir; no one but your very own issue shall be your heir.’ ⁵ He brought him outside and said, ‘Look towards heaven and count the stars, if you are able to count them.’ Then he said to him, ‘So shall your descendants be.’