Bringeth forth - As a tree full of life and sap brings forth its fruit. So the "froward tongue" is like a tree that brings forth evil and not good fruit; it "shall be cut down." The abuse of God's gift of speech will lead ultimately to its forfeiture. There shall, at last, be the silence of shame and confusion.

The froward tongue shall be cut out - This probably alludes to the punishment of cutting out the tongue for blasphemy, treasonable speeches, profane swearing, or such like. The tunge of schrewis schal perishen. - Old MS. Bible. Were the tongue of every shrew or scold to be extracted, we should soon have much less noise in the world.

The mouth of the just bringeth forth wisdom,.... As the earth brings forth its increase, and a tree brings forth its fruit; hence speech is called the fruit of the lips; wisdom is good fruit; a good man is comparable to the fruitful earth, and to a good tree; whose mouth brings forth wise things in abundance, which are very pleasant and profitable; not worldly wisdom, much less devilish; not merely natural wisdom, but spiritual and evangelical; see Psalm 37:30;
but the froward tongue shall be cut out; or "cut down" (z); as an unprofitable tree, which brings forth nothing but perverse things; things contrary to God and good men, to truth and right reason, to the light of nature, the law of God, and Gospel of Christ. Such "a tongue of perversities" (a), as it may be rendered, that brings forth blasphemies against God, his tabernacle and his saints, as the tongue of antichrist does, deserves to be cut out, as the tongue of a blasphemer.
(z) "succidetur", Pagninus, Montanus, Mercerus, Gejerus. (a) "lingua perversitatum", Montanus, Junius & Tremeilius, Gejerus, Michaelis.

A good man discourses wisely for the benefit of others. But it is the sin, and will be the ruin of a wicked man, that he speaks what is displeasing to God, and provoking to those he converses with. The righteous is kept by the power of God; and nothing shall be able to separate him from the love of God which is in Christ Jesus.

bringeth forth--literally, "germinates" as a plant.
froward--(Compare Proverbs 2:12, Proverbs 2:14).
cut off--as an unproductive plant.

For the third time the favourite theme already handled in three appendixes is taken up:
The mouth of the righteous bringeth forth wisdom,
And the tongue of falsehood shall be rooted up.
Regarding the biblical comparison of thoughts with branches, and of words with flowers and fruits, vid., my Psychol. p. 181; and regarding the root נב (with its weaker אב), to swell up and to spring up (to well, grow, etc.), vid., what is said in the Comm. on Genesis on נביא, and in Isaiah on עוב. We use the word נוּב of that which sprouts or grows, and נבב of that which causes that something sprout; but also נוב may, after the manner of verbs of being full (Proverbs 3:10), of flowing (Gesen. 138, 1, Anm. 2), take the object accus. of that from which anything sprouts (Proverbs 24:31), or which sprouting, it raises up and brings forth (cf. Isaiah 57:19). The mouth of the righteous sprouts, brings forth (in Psalm 37:30, without a figure, יהגּה, i.e., utters) wisdom, which in all relations knows how to find out that which is truly good, and suitable for the end intended, and happily to unriddle difficult complications. The conception of wisdom, in itself practical (from חכם, to be thick = solid, firm), here gains such contents by the contrast: the tongue - whose character and fruit is falsehood, which has its delight in intentional perversions of fact, and thus increaseth complications (vid., regarding תּהפּכות, Proverbs 2:12) - is rooted up, whence it follows as regards the mouth of the righteous, that it continues for ever with that its wholesome fruit.