Romans 9:7-9

New Catholic Bible

⁷ and not all of Abraham’s children are his true descendants. On the contrary, “It is through Isaac that descendants will bear your name.”

⁸ In other words, it is not through physical descent that people are regarded as children of God. Rather, the children of the promise are those who are counted as descendants. ⁹ For this is how the promise was worded: “About this time next year I shall return, and Sarah will have a son.”