And God said: Truly, Sarah your wife shall bear you a son, and you shall call his name Isaac; I have established My covenant with him for a perpetual covenant, with his seed after him.

And God said to Abraham, Do not let your eyes quiver because of the lad or because of your maidservant. Whatever Sarah has said to you, listen to her voice; for in Isaac your Seed shall be called.

nor are they all children because they are the seed of Abraham; but, In Isaac your Seed shall be called.