15 And God said to Abraham, “As for your wife Sarai, you shall not call her Sarai, but her name shall be Sarah.
16 I will bless her; indeed, I will give you a son by her. I will bless her so that she shall give rise to nations; rulers of peoples shall issue from her.”
17 Abraham threw himself on his face and laughed, as he said to himself, “Can a child be born to a man a hundred years old, or can Sarah bear a child at ninety?”
18 And Abraham said to God, “O that Ishmael might live by Your favor!”
19 God said, “Nevertheless, Sarah your wife shall bear you a son, and you shall name him Isaac; and I will maintain My covenant with him as an everlasting covenant for his offspring to come.