1 Chronicles 1:28
The sons of Abraham: Isaac and Ishmael.
Genesis 16:11-16
Jehovah's angel also said: You are now with child and you will have a son. You shall name him Ishmael (means: God hears). Jehovah has heard of your misery.
Genesis 17:19-21
God replied: Yes, but your wife Sarah will bear you a son! You will call him Isaac. I will establish my covenant with him as a long lasting covenant for his descendants after him.
Genesis 21:2-5
Sarah became pregnant and bore a son to Abraham in his old age. It was at the very time God had promised him.
Genesis 21:9-10
Sarah saw that the son whom Hagar the Egyptian had borne to Abraham was laughing in mockery.
Genesis 21:12
God said to Abraham: Do not be upset about the boy and your slave. Listen to what Sarah says, because through Isaac your descendants will carry on your name.