Now we, brethren, as Isaac was, are the children of promise.
All Commentaries on Galatians 4:28 Go To Galatians 4
Irenaeus of Lyons
AD 202
As Paul does also testify, saying that we are children of Abraham because of the similarity of our faith, and the promise of inheritance.
Thus also the apostle says in the Epistle to the Galatians: "But ye, brethren, as Isaac was, are the children of the promise."