Genesis 21:2-6 New English Translation (NET)

2. So Sarah became pregnant and bore Abraham a son in his old age at the appointed time that God had told him.

3. Abraham named his son – whom Sarah bore to him – Isaac.

4. When his son Isaac was eight days old, Abraham circumcised him just as God had commanded him to do.

5. (Now Abraham was a hundred years old when his son Isaac was born to him.)

6. Sarah said, “God has made me laugh. Everyone who hears about this will laugh with me.”

Genesis 21