Galatians 3:8 - Matthew Poole's English Annotations on the Holy Bible

The Holy Ghost in Scripture (by whose inspiration the Scripture was written) foreseeing, or knowing, the counsels and designs of God, that the heathen (when the fulness of times as to them should come) should be justified through faith in Christ, preached the same doctrine before unto Abraham; so as it is no new doctrine; the gospel which we now preach unto you, was long since revealed unto Abraham, who saw Christ's day, and rejoiced, 1 Thessalonians 8:56. To prove which, he quoteth the promise, Genesis 12:3, where God tells Abraham, that in him all the nations of the earth should be blessed; which quotation of it by the apostle in this place informeth us, that it is to be understood of those spiritual blessings which are in Christ Jesus. For all the nations of the earth were no otherwise blessed in Abraham, than as Christ (who is called the desire of all nations, and he in whom the Gentiles should trust, and a light to enlighten the Gentiles) descended from Abraham.