What shall the tongue of deceit give thee? [1] The Prophet aggravates the malice of his enemies by asserting that they were so wickedly inclined as to be driven to evil speaking when they saw no prospect of deriving any advantage from such a course of conduct. He however seems to express more than this, -- he seems farther to intimate, that after they have poured forth all the venom of their calumnies, their attempts will nevertheless be vain and ineffectual. As God is the maintainer of the innocence of his servants, David, inspired with hope from this truth, rises up against them with heroic courage, as if about to triumph over the whole crowd of his calumniators, reproaching them for doing nothing else than betraying an impotent passion for evil speaking, which God at length would cause to recoil upon their own heads. It is a consideration well fitted to assuage the grief of all the godly, when their good name is unrighteously wounded by calumniators, that such malicious characters will gain nothing thereby in the end, because God will disappoint their expectation.

Footnotes

1 - The Psalmist here addresses himself in particular to his traducers.

What shall be given unto thee? - Margin, "What shall the deceitful tongue give unto thee;" or, "what shall it profit thee?" Luther, "What can the false tongue do?" Others render this, "How will God punish thee?" Others, "What will he (God) give to thee?" That is, What recompence can you expect from God for these malignant calumnies? A literal translation of this verse would be, "What shall the tongue of deceit give to thee, and what shall it add to thee?" - referring to the offender himself. The essential idea is, What will be the result of such conduct? What must be expected to follow from it? That is, either
(a) from the unprofitableness of such a course; or
(b) from the natural consequences to one's reputation and happiness; or
(c) from the judgment of God.
The answer to these questions is found in Psalm 120:4.
Or what shall be done unto thee? - Margin, as in Hebrew, "added." What must be the consequence of this? what will follow?
Thou false tongue - This may be either an address to the tongue itself, or, as above, the word "tongue" may be used as the nominative to the verbs in the sentence. The sense is not materially affected either way.

What shall be given unto thee? - Thou art worthy of the heaviest punishments.

What shall be given unto thee? or what shall be done unto thee, thou (c) false tongue?
(c) He assured himself that God would turn their craft to their own destruction.

What shall be given unto thee?.... Or, "what shall it give unto thee?" (s) That is, what shall the deceitful tongue give unto thee, O my soul? or to thee, to anyone that hears and reads this psalm? It is capable of giving thee a deal of trouble, of doing thee a deal of mischief; and of injuring thy character, and hurting thy peace and comfort, if permitted;
or what shall be done unto thee, thou false tongue? or, "what shall the false tongue add unto thee?" (t) it shall increase thy sorrows and distress: or rather, what gain, profit, and advantage, shall the deceitful tongue get to itself by its lies and deceit? none at all; it may do harm to others, but gets no good to itself; see Isaiah 28:15; Or, "what shall he (God) give unto thee?" (u) or, "what shall he add unto thee, thou false tongue?" so Jarchi. What punishment will not he inflict upon thee, who hates lying lips? what plagues will not he add unto thee, who knows all the deceit that is in thee, and spoken by thee? The answer is as follows:
(s) "quid dabit tibi", Pagninus, Montanus, Musculus, Gejerus; so Junius & Tremellius, Piscator. (t) "et quid addet tibi", Montanus, Castalio; so Junius & Tremellius, Piscator, Cocceius. (u) "Quid inferat tibi (Deus) aut quem rem adhibeat tibi, O lingua dolosa?" Tigurine version.