The LORD came to help Sarah and did for her what he had promised.
So she became pregnant, and at the exact time God had promised, she gave birth to a son for Abraham in his old age.
Abraham named his newborn son Isaac.
When Isaac was eight days old, Abraham circumcised him as God had commanded.
Abraham was 100 years old when his son Isaac was born.
Sarah said, "God has brought me laughter, and everyone who hears about this will laugh with me.
Who would have predicted to Abraham that Sarah would nurse children? Yet, I have given him a son in his old age."
The child grew and was weaned. On the day Isaac was weaned, Abraham held a big feast.
Sarah saw that Abraham's son by Hagar the Egyptian was laughing at Isaac.