TSK
Treasury of Scripture Knowledge references in WEB.
God said, "No, but Sarah, your wife, will bear you a son. You shall call his name Isaac. I will establish my covenant with him for an everlasting covenant for his seed after him.
He said, "I will certainly return to you when the season comes round. Behold, Sarah your wife will have a son." Sarah heard in the tent door, which was behind him.
I took your father Abraham from beyond the River, and led him throughout all the land of Canaan, and multiplied his seed, and gave him Isaac.
After these days Elizabeth, his wife, conceived, and she hid herself five months, saying,
He gave him the covenant of circumcision. So Abraham became the father of Isaac, and circumcised him the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve patriarchs.
For it is written that Abraham had two sons, one by the handmaid, and one by the free woman.