Hilary of Poitiers

The Pharisees, who thought that the key of the kingdom of heaven was in their hands, accused the disciples of doing what was not lawful to do; whereon the Lord reminded them of deeds in which, under the guise of facts, a prophecy was concealed; and that He might shew the power of all things, He further added, that it contained the form of that work which was to be, Had ye known what that meaneth, I will have mercy; for the work of our salvation is not in the sacrifice of the Law, but in mercy; and the Law having ceased, we are saved by the mercy of God. Which gift if they had understood they would not have condemned the innocent, that is His Apostles, whom in their jealousy they were to accuse of having transgressed the Law, where the old sacrifices having ceased, the new dispensation of mercy came through them to the aid of all.