Galatians 4:23
But he who was of the bondwoman was born according to the flesh, but he of the freewoman was born through the promise.
Hebrews 11:11
By faith also Sara herself being sterile received strength to conceive seed and was delivered of a child when she was past age, because she believed him to be faithful who had promised.
Genesis 18:10-14
Then he said, I will certainly return unto thee according to the time of life; and, behold, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him.
Genesis 21:1-2
And the LORD visited Sarah as he had said, and the LORD did with Sarah as he had spoken.
Romans 9:7-8
neither, because they are the seed of Abraham, are all sons, but, In Isaac shall thy seed be called.
Genesis 17:15-19
And God said unto Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be.
Romans 4:18-21
Who believed to wait against all hope, that he might become the father of many Gentiles, according to that which had been spoken unto him, So shall thy seed be.
Romans 10:8
But what does it say? The word is near thee, even in thy mouth and in thy heart: that is, the word of faith, which we preach,
Galatians 4:28-29
So that we, brethren, as Isaac was, are the children of promise.