John Gill Bible Commentary

Let the lying lips be put to silence,.... Being convicted of the lies told by them, and so silenced and confounded; or being cut off and destroyed, as all such will be in the Lord's own time, Psa 12:3. It is very likely the psalmist may have respect either to Doeg the Edomite, who loved lying rather than righteousness; or to others that were about Saul, who lying said to him that David sought his harm, even to take away his kingdom and his life, Psa 52:3; which speak grievous things proudly and contemptuously against the righteous; meaning himself; not that he thought himself righteous in the sight of God by any righteousness of his own, but by the righteousness of Christ imputed to him; see Psa 143:2. Though he may have regard here to the righteousness of his cause before men, and assert himself righteous, as he might with respect to the "grievous things", the hard and lying speeches, which were spoken against him, in a proud, haughty, and contemptuous manner. And it is no unusual thing for such false charges to be brought against righteous men; nay, such hard speeches were spoken by ungodly men against Jesus Christ the righteous himself, Jde 1:15. The Targum interprets it of "reproaches".