The man of tongue, [1] etc. Some understand by this the loquacious man, but the sense is too restricted; nor is the reference to a reproachful, garrulous, vain and boastful man, but the man of virulence, who wars by deceit and calumny, and not openly. This is plain from what is said of the other class of persons in the subsequent part of the sentence, that his enemies were given to open violence as well as to treachery and cunning -- like the lion as well as the wolf -- as formerly he complained that the poison of the asp or viper was under their lips. The words run in the future tense, and many interpreters construe them into the optative form, or into a prayer; but I prefer retaining the future tense, as David does not appear so much to pray, as to look forward to a coming deliverance. Whether his enemies wrought by treachery, or by open violence, he looks forward to God as his deliverer. The figure drawn from hunting is expressive. The hunter, by spreading his toils on all sides, leaves no way of escape for the wild beast; and the ungodly cannot by any subterfuge elude the divine judgments. Mischief hunts them into banishment's, for the more they look for impunity and escape, they only precipitate themselves more certainly upon destruction.

Footnotes

1 - "A man, of tongue, i.e., of evil tongue; a slanderer or detractor." -- Phillips. The Bible translation renders the phrase "an evil speaker;" and the Chaldee Paraphrase has "the man of detraction, with a three-forked tongue;" because such a man wounds three at once -- the receiver, the sufferer, and himself.

Let not an evil speaker - literally, "A man of tongue." That is, a man whom the tongue rules; a man of an unbridled tongue; a man who does not control his tongue. See the notes at James 3:2-12.
Be established in the earth - Be successful or prosperous; let him not carry out his designs. It is not desirable that a man should prosper in such purposes; and therefore, this is not a prayer of malignity, but of benevolence.
Evil shall hunt the violent man - More literally, "A man of violence - a bad man - they shall hunt him down speedily;" or, "let him be hunted down speedily. Let him who forms a project of violence and wrong - a bad man - be hunted as the beasts of prey are, and let his destruction come quickly." Margin, "Let him be hunted to his overthrow." But the explanation now given suits the connection, and is a literal expression of the sense of the original.

Let not an evil speaker be established - איש לשון ish lashon, "a man of tongue." There is much force in the rendering of this clause in the Chaldee גבר דמשתעי לישן תליתי gebar demishtai lishan telithai, "The man of detraction, or inflammation, with the three-forked tongue." He whose tongue is set on fire from hell; the tale-bearer, slanderer, and dealer in scandal: with the three-forked tongue; wounding three at once: his neiphbour whom he slanders; the person who receives the slander; and himself who deals in it. What a just description of a character which God, angels, and good men must detest! Let not such a one be established in the land; let him be unmasked; let no person trust him; and let all join together to hoot him out of society. "He shall be hunted by the angel of death, and thrust into hell." - Chaldee.

Let not an evil speaker be established in the earth: evil shall (i) hunt the violent man to overthrow [him].
(i) God's plagues will light on him in such sort, that he will not escape.

Let not an evil speaker be established in the earth,.... One that sets his mouth against the heavens, and speaks evil of God; of his being, perfections, purposes, and providences: whose tongue walks through the earth, and speaks evil of all men, even of dignities; and especially of the saints of the most High, and of the Gospel and ways of Christ. Or, "a men of tongue" (q); that uses his tongue in an ill way, in detractions and slanders (r); in blaspheming God, his name and tabernacle, and those that dwell therein, as antichrist, Revelation 13:5; a man that calumniates with a triple tongue, so the Targum; like a serpent, whose tongue seems to be so sometimes. Kimchi applies this to Doeg, and Jarchi to Esau. The request is, that such an one might not be established in the earth; in the land of the living, as the Targum; might not increase and flourish in worldly substance, or be continued in his posterity; but be rooted out of the earth, and he and his be no more; see Psalm 3:4;
evil shall hunt the violent man to overthrow him; or "to impulsions" (s): to drive him from evil to evil, as Kimchi. The sense is, that the evil of punishment shall hunt him, as a beast of prey is hunted; it shall closely pursue him and overtake him, and seize on him, and thrust him down to utter ruin and destruction. The Targum is,
"the injurious wicked man, let the angel of death hunt, and drive into hell.''
Of the violent man, see Psalm 140:1; he who purposed to overthrow David, he was persuaded would be overthrown himself. This clause teaches us how to understand the rest; for though they are delivered out as wishes and imprecations, yet are prophetic, and are strongly expressive of the certainty of the things imprecated.
(q) "vir linguae", Pagninus, Montanus, Cocceius, Gejerus, Michaelis. (r) So the word "tongue" is used in Cicero, "Si linguas minus facila possimus", Epist. l. 9. 2. (s) "ad impulsiones", Montanus.

an evil speaker--or, "slanderer" will not be tolerated (Psalm 101:7). The last clause may be translated: "an evil (man) He (God) shall hunt," &c.