18 He goes on: “Those who sought after My faults had spoken vanity.” What is, “sought after My faults”? They sought after many things, and found them not. Perhaps He may have meant this: “They sought for criminal charges against me.” For they sought for somewhat to say against Him, and “they found not.” For they were seeking to find evil things to say of “the Good;” crimes of the Innocent; When would they find such things in Him, who had no sin? But because they had to seek for sins in Him who had no sin, it remained for them to invent that which they could not find.
Therefore, “those who sought after My faults have spoken vanity,” i.e., untruth, “and imagined deceit all the day long;” that is, they meditated treachery without intermission. You know how atrocious false-witness was borne against the Lord, before He suffered. You know how atrocious false-witness was borne against Him, even after His resurrection. For those soldiers who watched His sepulchre of whom Isaiah spoke, “I will appoint the wicked for His burial” (for they were wicked men, and would not speak the truth, and being bribed they disseminated a lie), consider what “vanity” they spoke. They also were examined, and they said, “While we slept, His disciples came and stole Him away.” This it is, “to speak vanity.” For if they were sleeping, how could they know what had been done?
Source: The Enarrations, or Expositions, on the Psalms (New Advent)