Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.

That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.

And God said unto Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be.

Then Abraham fell upon his face, and laughed, and said in his heart, Shall a child be born unto him that is an hundred years old? and shall Sarah, that is ninety years old, bear?

And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac: and I will establish my covenant with him for an everlasting covenant, and with his seed after him.

And he said, I will certainly return unto thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him.

Therefore Sarah laughed within herself, saying, After I am waxed old shall I have pleasure, my lord being old also?

Is any thing too hard for the LORD? At the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son.

And the LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken.

For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.

Who against hope believed in hope, that he might become the father of many nations, according to that which was spoken, So shall thy seed be.

He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God;

But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach;

Through faith also Sara herself received strength to conceive seed, and was delivered of a child when she was past age, because she judged him faithful who had promised.