7 Because of this there follows in the Psalm, “You have loved all words of sinking under”. Rescue therefore yourself, if you can, from sinking under. From shipwreck you are fleeing, and dost embrace lead! If you will not sink, catch at a plank, be borne on wood, let the Cross carry you through. But now because you are a Doeg the Edomite, a “motion,” and “of earth,” you do what? “You have loved all words of sinking-under, a tongue deceitful.” This has preceded, words of sinking-under have followed a tongue deceitful. What is a tongue deceitful? A minister of guile is a tongue deceitful, of men bearing one thing in heart, another thing from mouth bringing forth. But in these is overthrowing, in these sinking under.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)