Psalm 50:19

Thou givest thy mouth to evil, and thy tongue frameth deceit.

Thou givest thy mouth to evil,.... To speak evil things against Christ, his doctrines, ordinances, ministers and people; and to deliver out evil doctrines, pernicious to the souls of men;

and thy tongue frameth deceit; puts and joins together deceitful words in a very artful manner, by which simple and unstable minds are beguiled.