Galatians 3:8

3:8 And the scripture, foreseeing that God would justify the Gentiles by faith, proclaimed the gospel to Abraham ahead of time, saying, “All the nations will be blessed in you.”

Galatians 3:16

3:16 Now the promises were spoken to Abraham and to his descendant. Scripture does not say, “and to the descendants,” referring to many, but “and to your descendant,” referring to one, who is Christ.

Galatians 4:30

4:30 But what does the scripture say? “Throw out the slave woman and her son, for the son of the slave woman will not share the inheritance with the son” of the free woman.