8. And--Greek, "Moreover."
      foreseeing--One great excellency of Scripture is, that in it all points liable ever to be controverted, are, with prescient wisdom, decided in the most appropriate language.
      would justify--rather, "justifieth." Present indicative. It is now, and at all times, God's one way of justification.
      the heathen--rather, "the Gentiles"; or "the nations," as the same Greek is translated at the end of the verse. God justifieth the Jews, too, "by faith, not by works." But he specifies the Gentiles in particular here, as it was their case that was in question, the Galatians being Gentiles.
      preached before the gospel--"announced beforehand the Gospel." For the "promise" was substantially the Gospel by anticipation. Compare Joh 8:56; Heb 4:2. A proof that "the old fathers did not look only for transitory promises" [Article VII, Church of England]. Thus the Gospel, in its essential germ, is older than the law though the full development of the former is subsequent to the latter.
      In thee--not "in thy seed," which is a point not here raised; but strictly "in thee," as followers of thy faith, it having first shown the way to justification before God [ALFORD]; or "in thee," as Father of the promised seed, namely, Christ (Ga 3:16), who is the Object of faith (Ge 22:18; Ps 72:17), and imitating thy faith (see on Ga 3:9).
      all nations--or as above, "all the Gentiles" (Ge 12:3; 18:18; 22:18).
      be blessed--an act of grace, not something earned by works. The blessing of justification was to Abraham by faith in the promise, not by works. So to those who follow Abraham, the father of the faithful, the blessing, that is, justification, comes purely by faith in Him who is the subject of the promise.

JFB.