Hebrews 2:16

2:16 For surely his concern is not for angels, but he is concerned for Abraham’s descendants.

Hebrews 11:18

11:18 God had told him, “Through Isaac descendants will carry on your name,”

Hebrews 11:11

11:11 By faith, even though Sarah herself was barren and he was too old, he received the ability to procreate, because he regarded the one who had given the promise to be trustworthy.