Augustine of Hippo

Because of this there follows in the Psalm, "You have loved all words of sinking under" [Psalm 52:5]. 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.