Psalms 31:18

Let the lying lips be put to silence - See the notes at Psalms 12:2. The lips which speak lies. The reference here is especially to those who had spoken in this manner against the psalmist himself, though he makes the language general, or prays in general that God would silence all liars: a prayer certainly in which all persons may properly join.

Which speak grievous things - Margin, “a hard thing.” The Hebrew word - עתק ‛âthâq - means “bold, impudent, wicked.” Gesenius, Lexicon. The phrase here means, therefore, to speak wickedly, or to speak in a bold, reckless, impudent manner; that is, without regard to the truth of what is said.

Proudly and contemptuously - Hebrew, in pride and contempt: that is, in a manner which shows that they are proud of themselves and despise others. Slander always perhaps implies this. People are secretly proud of themselves; or they “desire” to cherish an exalted opinion of themselves, and to have others entertain the same opinion of them; and hence, if they cannot exalt themselves by their own merit, as they wish, they endeavor to humble others below their real merit, and to a level lower than themselves, by detraction.