John Chrysostom — as excerpted in the Catena Aurea on John 1:16-17

“(Hom. xiv. [xiii.] sparsim.) Or we have received grace for grace; that is, the new in the place of the old. For as there is a justice and a justice besides, an adoption and another adoption, a circumcision and another circumcision; so is there a grace and another grace: only the one being a type, the other a reality. He brings in the words to shew that the Jews as well as ourselves are saved by grace: it being of mercy and grace that they received the law. Next, after he has said, Grace for grace, he adds something to shew the magnitude of the gift; For the law was given by Moses, but grace and truth were made by Jesus Christ. John when comparing himself with Christ above had said, He is preferred before me: but the Evangelist draws a comparison between Christ, and one much more in admiration with the Jews than John, viz. Moses. And observe his wisdom. He does not draw the comparison between the persons, but the things, contrasting grace and truth to the law: the latter of which he says was given, a word only applying to an administrator; the former made, as we should speak of a king, who does every thing by his power: though in this King it would be with grace also, because that with power He remitted all sins. Now His grace is shewn in His gift of Baptism, and our adoption by the Holy Spirit, and many other things; but to have a better insight into what the truth is, we should study the figures of the old law: for what was to be accomplished in the New Testament, is prefigured in the Old, Christ at His Coming filling up the figure. Thus was the figure given by Moses, but the truth made by Christ.”