Galatians 4:21-23

Tell me, you who want to live under the law, do you know what the law actually says? The Scriptures say that Abraham had two sons, one from his slave wife and one from his freeborn wife. The son of the slave wife was born in a human attempt to bring about the fulfillment of God’s promise. But the son of the freeborn wife was born as God’s own fulfillment of his promise.