Galatians 4:23
But the one by the female slave was born according to human descent, and the one by the free woman through the promise,
Hebrews 11:11
By faith also, {with Sarah}, he received {the ability to procreate} even {past the normal age}, because he regarded the one who had promised [to be] faithful.
Genesis 18:10-14
And he said, "I will certainly return to you {in the spring}, and look, Sarah your wife [will have] a son." Now Sarah [was] listening at the doorway of the tent, and which [was] behind him.
Genesis 21:1-2
And Yahweh visited Sarah as he had said. And Yahweh did to Sarah as he had promised.
Romans 9:7-8
nor [are they] all children because they are descendants of Abraham, but "In Isaac will your descendants be named."
Genesis 17:15-19
And God said to Abraham, "[as for] Sarai your wife, you shall not call her name Sarai, for Sarah [shall be] her name.
Romans 4:18-21
who against hope believed in hope, so that he became the father of many nations, according to what was said, "so will your descendants be."
Romans 10:8
But what does it say? "The word is near to you, in your mouth and in your heart" (that is, the word of faith that we proclaim),
Galatians 4:28-29
But you, brothers, are children of the promise, just as Isaac.