Here the word "mouth" is a metonym for the writer. The abstract noun "wickedness" can be translated by an adjective. The abstract noun "deceit" can be translated by a verb. Alternate translation: "Everything he says is wicked, and he wants to deceive others" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-abstractnouns]])