As God changed Abraham’s name earlier in Chapter 17, God now changes his wife’s name to Sarah. And because it seems that Abraham is still not understanding, God again makes clear the child of the promise will be from within the bounds of the Genesis 2 marriage covenant Abraham has with his singular wife, Sarah. And when there is a question of who will be the heir, God tells Abraham it will be the child to come from Sarah, and his name will be Isaac.
What is Into the Word with Bryce Ferguson?
An Exegetical teaching of God's Word