“Sarah conceived, and bore Abraham a son in his old age, at the set time of which God had spoken to him.”
Genesis 21:2 (WEB)
Context Reading
1Yahweh visited Sarah as he had said, and Yahweh did to Sarah as he had spoken. 2Sarah conceived, and bore Abraham a son in his old age, at the set time of which God had spoken to him. 3Abraham called his son who was born to him, whom Sarah bore to him, Isaac. 4Abraham circumcised his son, Isaac, when he was eight days old, as God had commanded him.