John Chrysostom
Having proved what was said by the example of Abraham, the Apostle turns to David, who confirms the same thought. What then does David say, and whom does he call blessed? The one who boasts in works, or the one counted worthy of grace, who has received forgiveness of sins and the gift?
When I speak of blessedness, I mean the summit of all good things. As righteousness is higher than wages, so blessedness is higher than righteousness. Therefore, after proving the superiority of righteousness not only by the example of Abraham, who received it, but also by arguments from reason, saying, "He has something to boast of, but not before God" (Rom 4:2), the Apostle again unfolds its importance in another way. He appeals to David, who testifies in its favor.
David too, as the Apostle says, calls the one justified through faith blessed, saying: Rom 4:7, "Blessed are those whose lawless deeds are forgiven."