Romans 9:7-9

Thomson(i) 7 nor are they all children, because they are of the race of Abraham; but in Isaak a seed shall be called for thee. 8 That is to say, It is not the children of the flesh who are the children of God; but the children of the promise are reckoned for seed. 9 For this is the word of the promise. "About this time twelve month I will come and Sarah shall have a son."