New Defender's Study Bible Notes
21:7 his old age. When God heals miraculously, he does it instantly and completely. Sarah’s body was so rejuvenated that although she was ninety years old, she was able both to bear a child and even to nurse him. Abraham was so “young” again that even at one hundred years of age he could later father six more sons of Keturah many years later, after Sarah’s death.