8 For, “if in this life only,” says the Apostle, “we have hope in Christ, we are of all men most miserable.” For what reason were the Martyrs condemned to beasts? What is that good? Can it be declared? By what means, or what tongue can tell it? Or what ears can hear it? That indeed, “Neither ear has heard, nor has it entered into man's heart:” only let us love, only let us grow in grace: ye see, then, that battles are not wanting, and that we fight with our lusts.
We fight outwardly with unbelieving and disobedient men; we fight inwardly with carnal suggestions and perturbations: we everywhere as yet fight....What sort of peace then is this? One from Jerusalem, for Jerusalem is interpreted, A vision of Peace. Thus then “may thou see the good things that are of Jerusalem,” and that, “all your life long— and may thou see,” not only your children, but, “your children's children.” What means, Your children? Your works which thou here dost. Who are your children's children? The fruits of your works. You give alms: these are your children: for the sake of your alms you receive everlasting life, these are your children's children. “May you see your children's children;” and there shall be “peace upon Israel”, the last words of the Psalm....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)