Joyful Elderly Woman Embracing a NewbornBible World

Genesis 21:2

For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.

At the set time of which He had spoken, God fulfilled His promise to Abraham and Sarah by giving them a son in their old age. The child came at the appointed time He had announced beforehand, not before and not after. Abraham received that son because he believed God, who had promised the child and faithfully kept His word.

That believing reception shows the son was given through faith in a promise-keeping God. Faith laid hold of the divine word, and God's faithfulness answered it with fulfillment in old age. The gift therefore stands as proof that God does what He says He will do.

The birth also reveals God's unlimited power to accomplish what seems impossible to men. What nature and age declared hopeless, He performed, proving that nothing is impossible with Him. Zacharias should have remembered this example when the angel promised a son to him and his wife in their old age. Had he kept Abraham and Sarah's experience in mind, he would not have doubted on account of age as he did.