23 “And the Lord shall recompense them according to their works, and after their own malice; the Lord our God shall destroy them”. The words, “after their own malice,” are not said without meaning. I am benefited through them: and yet it is said to be their malice, and not their benefits. For assuredly He tries us, scourges us, by means of the wicked. To prepare us for what does He scourge us? Confessedly for the kingdom of heaven. “For He scourges every son whom He receives; for what son is he whom the father chastens not?” and when God does this, He is teaching us in order to an eternal heritage: and this learning He often gives us by means of wicked men, through whom He tries and perfects our love, which He does will to be extended even to our enemies....Thus also they who persecuted the Martyrs, by persecuting them on earth, sent them into heaven: knowingly they caused them the loss of the present life, while unconsciously they were bestowing upon them the gain of a future life: but, nevertheless, unto all who persevered in their wicked hatred of the righteous, will God recompense after their own iniquities, and in their own malice will He destroy them. For as the goodness of the righteous is hurtful unto the wicked, so is the iniquity of the wicked beneficial unto the righteous....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)