Romans 9:8-10

Amplified Bible

⁸ That is, it is not the children of the body [Abraham’s natural descendants] who are God’s children, but it is the children of the promise who are counted as [Abraham’s true] descendants. ⁹ For this is what the promise said: “About this time [next year] I will come, and Sarah shall have a son.”^{(A) 10} And not only that, but this too: Rebekah conceived twin sons by one man [under the same circumstances], by our father Isaac;