2 What in them will You slay? The Crucify, Crucify, which they cried out, not them that cried out. For they willed to blot out, cut off, destroy Christ: but Thou, by raising to life Christ, whom they willed to destroy, dost slay the “transgressions of their mouth, the discourse of their lips.” For in that He whom they cried out should be destroyed, lives, they are taken with dread: and that He whom on earth they despised, in heaven is adored by all nations, they wonder: thus are there slain the transgressions of them, and the discourse of their lips. What is, “let them be taken in their pride”? Because to no purpose have strong men rushed on, and it has fallen out to them as it were to think themselves to have done somewhat, and they have prevailed against the Lord. They were able to crucify a man, weakness might prevail and virtue be slain; and they thought themselves somewhat, as it were strong men, as it were mighty men, as it were prevailing, as it were a lion prepared for prey, as it were fat bulls, as of them in another place he makes mention: “Fat bulls have beset me.” But what have they done in the case of Christ? Not life, but death they have slain....And what now has come to pass in those men that have been converted? For it was told to them that He whom they slew rose again. They believed Him to have risen again, because they saw that He, being in Heaven, thence sent the Holy Spirit, and filled those that on Him believed; and they found themselves to have condemned nought, and to have done nought. Their doing issued in emptiness, the sin remained. Because therefore the doing was made void, but the sin remained upon the doers; they were taken in their pride, they saw themselves under their iniquity. It remained therefore for them to confess the sin, and for Him to pardon, that had given Himself up to sinners, and to forgive His death, having been slain by men dead, and making alive men dead. They were taken therefore in their pride.
3. “And out of cursing and lying shall be declared consummations, in anger of consummation, and they shall not be.” This too with difficulty is understood, to what is joined the “and they shall not be.” What shall they not be? Let us therefore examine the context above: when they shall have been taken in their pride, “there shall be declared out of cursing and lying consummations.” What are consummations? Perfections: for to be consummated, is to be perfected. One thing it is to be consummated, another thing to be consumed. For a thing is consummated which is so finished as that it is perfected: a thing is consumed which is so finished that it is not. Pride would not suffer a man to be perfected, nothing so much hinders perfection. For let your Love attend a little to what I am saying; and see an evil very pernicious, very much to be guarded against. What sort of evil do ye think it is? How long could I enlarge upon how much evil there is in pride? The devil on that account alone is to be punished. Certes he is the chief of all sinners: certes he is the tempter to sin: to him is not ascribed adultery, not wine-bibbing, not fornication, not the robbing of others' goods: by pride alone he fell. And since pride's companion is envy, it must needs be that a proud man should envy....In a word, all vices in evil-doings are to be feared, pride in well-doings is more to be feared. It is no wonder, then, that so humble is the Apostle, as to say, “When I am made weak, then I am strong.” For lest he should himself be tempted by this sin, what sort of medicine does he say was applied to him against swelling by the Physician, who knew what He was healing? “Lest by the greatness,” he says, “of the revelations I should be exalted, there was given to me a thorn of my flesh, the angel of Satan, to buffet me: wherefore thrice the Lord I besought, that it should depart from me: and He said to me, My grace is sufficient for you, for virtue in weakness is made perfect.” See what the consummations are. An Apostle, the teacher of Gentiles, father of the faithful through the Gospel, received a thorn of the flesh whereby he might be buffeted. Which of us would dare to say this, unless he had not been ashamed to confess this? For if we shall have said that Paul had not suffered this; while to him as it were honour we give, a liar we make him. But because truthful he is, and truth he has spoken; it behooves us to believe that there was given to him an angel of Satan, lest by the greatness of the revelations he should be exalted. Behold how much to be feared is the serpent of pride....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)