John Calvin Commentary Genesis 20:17

"And Abraham prayed unto God. And God healed Abimelech, and his wife, and his maid-servants. And they bare children." — Genesis 20:17 (ASV)

So Abraham prayed. In two respects the wonderful favor of God towards Abraham was apparent; first, that, with outstretched hand, He avenged the injury done to him; and secondly, that, through Abraham’s prayer, He became pacified towards the house of Abimelech. It was necessary to declare that the house of Abimelech had been healed in answer to Abraham’s prayers, so that by such a benefit, the inhabitants might be more closely bound to him.

A question, however, may be raised concerning the kind of punishment described in the expression "the whole house was barren." For if Abraham had gone into the land of Gerar after Sarah had conceived, and if the whole of what Moses has here related was fulfilled before Isaac was born, how was it possible that, in so short a time, this sterility should be manifest?

If we were to say that God’s judgment was then made clear, in a way unknown to us, the answer would not be inappropriate. Yet I am not certain that the sequence of the history has not been inverted. The more probable supposition might seem to be that Abraham had already been living in Gerar when Isaac was promised to him, but that the part previously omitted is now inserted by Moses.

If anyone should object that Abraham lived in Mamre until the destruction of Sodom, there would be nothing absurd in believing that what Moses relates here had taken place previously. Yet, since the correct notation of time does little for the confirmation of our faith, I leave both opinions undecided.

CHAPTER 21.