Thematic Bible: Her miraculous conception of isaac

And God said to Abraham, As for Sarai your wife, you shall not call her name Sarai, but her name shall be Sarah. And I will bless her, and give you a son also of her. Yes, I will bless her, and she shall be a mother of nations, kings of people shall be from her. And Abraham fell upon his face and laughed, and said in his heart, Shall a child be born to him that is a hundred years old? And shall Sarah, who is ninety years old, bear? read more.
And Abraham said to God, Oh that Ishmael might live before You! And God said, Sarah your wife shall bear you a son indeed. And you shall call his name Isaac. And I will establish My covenant with him for an everlasting covenant, and with his seed after him. And as for Ishmael, I have heard you. Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly. He shall father twelve chiefs, and I will make him a great nation. But I will establish My covenant with Isaac, whom Sarah shall bear to you at this set time in the next year.

And they said to him, Where is Sarah your wife? And he said, Behold, in the tent. And He said, I will certainly return to you according to the time of life, and lo, Sarah your wife shall have a son. And Sarah heard in the tent door which was behind Him. Now Abraham and Sarah were old, far gone in days, and it had ceased to be with Sarah after the manner of women. read more.
Therefore Sarah laughed within herself, saying, After my being old, shall I have pleasure, my lord being old also? And Jehovah said to Abraham, Why did Sarah laugh, saying, Shall I, who am old, truly bear a child? Is anything too hard for Jehovah? At the time appointed I will return again, according to the time of life, and Sarah shall have a son. Then Sarah denied, saying, I did not laugh; for she was afraid. And He said, No, but you did laugh.