The tongue devises mischiefs; like a sharp razor, working deceitfully.…
The prominence given to sins of speech is peculiar. We should have expected high-handed violence rather than these. But the psalmist is tracking the deeds to their source; and it is not so much the tyrant's words as his love of a certain kind of words which is adduced as proof of his wickedness. These words have two characteristics in addition to boastfulness. They are false and destructive. They are, according to the forcible literal meaning in verse 4, "words of swallowing." They are, according to the literal meaning of "destructions" in verse 2, "yawning gulfs." Such words lead to acts which make a tyrant. They flow from perverted preference of evil to good. Thus the deeds of oppression are followed up to their den and birthplace.
(A. Maclaren, D. D.)
Parallel VersesKJV: Thy tongue deviseth mischiefs; like a sharp rasor, working deceitfully.