Romans 9:6-9

6But it is not that the word of God has taken no effect. For they are not all Israel who are of Israel,

7nor are they all children because they are the seed of Abraham; but, “In Isaac your seed shall be called.”

8That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted as the seed.

9For this is the word of promise: “At this time I will come and Sarah shall have a son.”