Romans 9:8-10

Young's Literal Translation

⁸ that is, the children of the flesh -- these [are] not children of God; but the children of the promise are reckoned for seed;

⁹ for the word of promise [is] this; `According to this time I will come, and there shall be to Sarah a son.'

¹⁰ And not only [so], but also Rebecca, having conceived by one -- Isaac our father --