Sarah conceived By faith Sarah received strength, (Hebrews 11:11,) to conceive seed, God, according to his promise, giving that strength. Abraham was old, and Sarah old, and both as good as dead, and then the promise took place.
Related Commentaries of Genesis 21:2
Genesis 21:2
2 For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.