Matthew Henry Commentary Psalms 140:8-13

"Grant not, O Jehovah, the desires of the wicked; Further not his evil device, [lest] they exalt themselves. Selah As for the head of those that compass me about, Let the mischief of their own lips cover them. Let burning coals fall upon them: Let them be cast into the fire, Into deep pits, whence they shall not rise. An evil speaker shall not be established in the earth: Evil shall hunt the violent man to overthrow him. I know that Jehovah will maintain the cause of the afflicted, And justice for the needy. Surely the righteous shall give thanks unto thy name: The upright shall dwell in thy presence." — Psalms 140:8-13 (ASV)

Believers may pray that God would not grant the desires of the wicked, nor further their evil devices. False accusers will bring mischief upon themselves, even the burning coals of Divine vengeance.

And surely the righteous will dwell in God's presence and give Him thanks forevermore. This is true thanksgiving, even “thanks-living”: this use we should make of all our deliverances: we should serve God more closely and cheerfully.

Those who, though evil spoken of and ill-used by men, are righteous in the sight of God, being justified by the righteousness of Christ, which is imputed to them and received by faith, as the effect of which they live soberly and righteously; these give thanks to the Lord for the righteousness by which they are made righteous, and for every blessing of grace and mercy of life.