A false witness that speaketh lies,.... Or, "that speaketh lies, even a false witness" (f); and so this is distinguished from a lying tongue, the second of these evils: this is the sin of bearing false witness against one's neighbour, a breach of the eighth command. It may be rendered, "he that bloweth lies" (g); that raises lies, and spreads them abroad, and swears to them, to the damage of others. This makes the sixth; and the seventh follows,
and him that soweth discord among brethren; whether in a natural relation, or in a civil society, or in a religious community.
(f) So Vatablus, Mercerus, &c. (g) "qui efflat mendacia", Piscator, Michaelis.

speaketh--literally, "breathes out," habitually speaks (Psalm 27:12; Acts 9:1).

The sixth: "A speaker of lies, a tongue of falsehood," is hateful to God. It is one subject which is thus doubly characterized. כּזבים are fictions, and שׁקר is the disfiguring (deformatio) of the actual facts. They are purposely placed together in this connection. The derivations of these synonyms are obscure; Frst gives to the former the root-idea of spinning (properly knotting together), and to the latter that of painting. כזבים is introduced to support שׁקר.
(Note: Isaak Albo thus distinguishes these synonyms in his dogmatic, bearing the title ספר עקרים, ii. 27.)
It would also be verbally permissible to interpret עד שׁקר in the sense of עדוּת שׁקר, like Proverbs 25:18, as in apposition to כזבים; but in the nearest parallel, Proverbs 14:15, the idea is personal, for it is said of the עד שׁקר that he breathes out lies. In that place there can be no doubt that the clause is a verbal one, and יפיח finitum, viz., Hiph. of פּוּח. This Hiph. signifies elsewhere also sufflare, Proverbs 20:8, afflare, Psalm 10:5; Ezekiel 21:26, perflare, Song 4:16, anhelare (desiderare), Psalm 12:6; Habakkuk 2:3, but with כזבים, efflare, a synonym to דּבּר, as הבּיע and הטּיף, which has (cf. Proverbs 12:17) no secondary meaning in use, but is mostly connected with כזבים, not without reference to the fact that that which is false is without reality and is nothing more than הבל ורוח. But what kind of a form is יפיח, where it is not, as Proverbs 14:5, the predicate of a verbal clause, but in connection with כזבים, as here and at Proverbs 14:25; Proverbs 19:5, Proverbs 19:9 (once with אמונה, Proverbs 12:17), is the subject of a substantival clause? That which lies nearest is to regard it as a noun formed from the fut. Hiph. Such formations we indeed meet only among proper names, such as יאיר, יכין, יקים; however, at least the one n. appell. יריב (an adversary) is found, which may be formed from the Hiph. as well as from the Kal. But should not the constr. of יפיח after the form יריב be יפיח? One does not escape from this consideration by deriving יפיח, after the forms יגיע, יחיל, ידיד, ישׁישׁ, and the like, from a secondary verb יפח, the existence of which is confirmed by Jeremiah 4:31, and from which also יפח, Psalm 27:12, appears to be derived, although it may be reduced also, after the form ירב (with יריב), to הפיח. But in this case also one expects as a connecting form יפיח like ידיד, as in reality יפח from יפח (cf. אבל, שׂמהי, from אבל, שׂמח). Shall it now be assumed that the Kametz is treated as fixed? This were contrary to rule, since it is not naturally long. Thus the connection is not that of the genitive. But if יפיח were a substantive formed with the preformative of the second modus like ילקוּט 1-Samuel 17:40, or were it a participial intensive form of active signification such as נביא, then the verbal force remaining in it is opposed to the usage of the language. There remains nothing further, therefore, than to regard יפיח as an attributive put in the place of a noun: one who breathes out; and there is a homogeneous example of this, for in any other way we cannot explain יוסיף, Ecclesiastes 1:18. In 19b the numeral proverb reaches its point. The chief of all that God hates is he who takes a fiendish delight in setting at variance men who stand nearly related. Thus this brief proverbial discourse rounds itself off, coming again to 14b as a refrain.