For they have whetted their tongue like a sword His enemies, in their rage, aimed at nothing less than his life, and yet what he complains of, more than all beside, is the poison with which their words were imbued. It is probable that he refers to the calumnious reports which he knew to be falsely spread to his discredit, and with a view of damaging his reputation with the people. Their tongues he likens to swords; their bitter and venomous words to arrows. [1] And when he adds, that, they shoot against the upright and innocent, he is to be considered as contrasting his integrity with their unprincipled conduct. It inspired him with confidence in his religious addresses, to know that he could exonerate his own conscience from guilt, and that he was the object of undeserved attack by worthless and abandoned men. In mentioning that they shoot secretly and suddenly, he refers to the craft which characterised them. They were not only eagerly bent upon mischief, and intent in watching their opportunities, but so expert and quick in their movements, as to smite their victim before he could suspect danger. When we hear that David, who was a man in every respect so much more holy and upright in his conduct than ourselves, suffered from groundless aspersions upon his character, we have no reason to be surprised that we should be exposed to a similar trial. This comfort, at least, we always have, that we can betake ourselves to God, and obtain his defense of the upright cause. He takes particular notice of another circumstance, that they shot their empoisoned arrows from their lips without fear, or shame. This self-secure spirit argued a degree of abandoned presumption, in so far as they could persist in obstinately pursuing the conduct in which they had been repeatedly detected, and renew their desperate attempts, to the disregard of all fear of God or worldly shame.

Footnotes

1 - They have directed for their arrow a bitter word There may be, in these words, an allusion to the practice of fixing letters on arrows, and shooting or directing them where it was designed they should fall and be taken up. Thus the Jews say, Shebna and Joab sent letters to Sennacherib, acquainting him that all Israel were willing to make peace with him; but Hezekiah would not suffer them. Timoxenus and Artabazus sent letters to one another in this way at the siege of Potidaea. See Gill, in loco The word which they are said to direct as their arrow is called mr, mar, bitter, and this probably contains an allusion to poisoned arrows. The Chaldee paraphrast has "bending the bow and anointing the arrows," plainly intimating a conviction that such an allusion is implied. Poisoned arrows appear, from Job 6:4, to have been of very ancient use in Arabia. They were also used by many other nations in different parts of the world. Homer says of Ulysses, that he went to Ephyre, a city of Thessaly, in order to procure deadly poison for smearing his deadly-pointed arrows, Odyssey, Lib. 1, 50, 335-345. Virgil describes one of his heroes as eminently skillful in anointing the dart, and arming its steel with poison, Aen. Lib. 9, 50, 771. And Horace mentions the venenatoe sagittoe, the poisoned arrows of the ancient Moors in Africa, Lib. 1, Ode 22, 50, 3. Wherever this practice has prevailed, the poison employed has been of the most deadly kind, the slightest wound being followed by certain and almost instant death. This makes the language here strikingly expressive. David compares the calumnies his enemies launched against him to poisoned arrows.

Who whet their tongue like a sword - Who sharpen their tongue; that is, they utter words that will cut deep, or penetrate the soul. The idea is that of slander or reproach - the same idea which we have in Shakespeare (Cymbeline):
"'Tis slander;
Whose edge is sharper than the sword."
This comparison is a favorite one with David. Compare Psalm 52:2; Psalm 57:4; Psalm 59:7.
And bend their bows - That is, they prepare for this - as they make ready to shoot who bend their bows, and fix their arrows on the string. The idea here is, that this was deliberate, or was the result of counsel and purpose. It was not an outbreak of mere passion and excitement; it was by fixed design and careful preparation. See Psalm 11:2, note; Psalm 58:7, note.
Even bitter words - We apply the same term bitter now to words of malice and reproach.

Who whet their tongue like a sword - They devise the evil they shall speak, and meditate on the most provoking, injurious, and defamatory words; as the soldier whets his sword that he may thereby the better cut down his enemies.
Their arrows - bitter words - Their defamatory sayings are here represented as deadly as poisoned arrows; for to such is the allusion here made.

Who whet their tongue like a sword, [and] bend [their bows to shoot] their arrows, [even] (d) bitter words:
(d) False reports and slanders.

Who whet their tongue like a sword,.... Use cutting, wounding, killing, and devouring words; on which they set an edge, and make them keener and keener to hurt and ruin the characters and reputations of good men, and grieve and distress their minds;
and bend their bows to shoot their arrows, even bitter words; such are the these doctrines of heretical men, which are roots of bitterness, that defile some and trouble others; such are the oaths and curses of profane sinners, whose mouths are full of cursing and bitterness; and such are the blasphemies of antichrist against God, against his tabernacle, and against them that dwell therein; and such are the hard speeches spoken by ungodly sinners against Christ and his people; these are like arrows shot from a bow, and full of deadly poison. The Targum is
"they stretch out their bows, they anoint their arrows with deadly and bitter poison.''
There seems to be an allusion to fixing letters in arrows, and so shooting or directing them where it was desired they should fall and be taken up; so Timoxenus and Artobazus sent letters to one another in this way, at the siege of Potidaea (a): and after the same manner, the Jews say (b), Shebna and Joab sent letters to Sennacherib, acquainting him that all Israel were willing to make peace with him; but Hezekiah and Isaiah would not allow them to.
(a) Herodot. Urania, sive l. 8. c. 128. (b) Derash R. Aba in Kimchi in Psal. xi. 2.

Similar figures for slander (Psalm 57:4; Psalm 59:7).
bend--literally, "tread," or, "prepared." The allusion is to the mode of bending a bow by treading on it; here, and in Psalm 58:7, transferred to arrows.