The teacher cuts off the plea which people make when they have hurt their neighbor by lies, that they "did not mean mischief," that they were "only in fun." Such jesting is like that of the madman flinging firebrands or arrows.

As a mad man, who casteth firebrands, arrows, and death. Or the instruments of death, as Aben Ezra; or the sharp arrows of death, as the Targum and Syriac version; who casts firebrands into the houses and barns of his neighbours, to consume them; or arrows at their persons and cattle, to destroy them; or any other instruments of death, which none but a mad man, or one wickedly mad, would do. Or, "as one that makes himself mad" (e); that feigns himself mad, and, under colour of this, does mischief to his neighbour's person and property: or, "as one that hides himself" (f); that casts firebrands, arrows, and other deadly things, in a private way, so as not to be seen, and that it may not be known from whence they come: or, "as one that wearies himself" (g), so Jarchi; in doing mischief in such a way. The word in the Arabic language signifies to play and be in sport; and so it means one that does these things in sport, as it is a sport to a fool to do mischief; which sense agrees with what follows.
(e) "ut se habet qui iunsanum ne simulat", Piscator; "ut qui se insanire fingit", Cocceius. (f) "Sicut abscondit se", Pagninus, Mercerus, Gejerus. (g) "Ut sese fatigat", Tigurine version.

He that sins in jest, must repent in earnest, or his sin will be his ruin.

Such are reckless of results.

These verses form a tetrastich:
18 As a man who casteth brands,
And arrows, and death;
19 So is the man who deceiveth his neighbour,
And saith: I only make sport.
The old translations of מתלהלה are very diverse. Aquila has rendered it by κακοηθιζόμενος; Symmachus: πειρώμενοι; the Syr.: the vainglorious; the Targ.: מתּחת (from נחת), a successor (spiritually); Jerome: noxius (injurious; for which Luther: secret). There is thus no traditional translation. Kimchi explains the word by השׁתגע (Venet. ἐξεστώς); Aben Ezra by השׁתטה (from שׂטה), to behave thoughtlessly, foolishly; but both erroneously, confounding with it ותּלהּ, Genesis 47:13, which is formed from להה and not from לההּ, and is related to לאה, according to which מתלהלה would designate him who exerts himself (Rashi, המתיגע), or who is worn out (Saadia: who does not know what to do, and in weariness passes his time). The root לההּ (להּ), whence the reflex form התלהלהּ, like התמהמהּ, from מההּ, מהּ) leads to another primary idea. The root להּ presents in (Arab.) âliha (vid., Fleischer in the Comm. zur Genesis, p. 57), waliha, and taliha, formed from the 8th form of this verb (aittalah), the fundamental meaning of internal and external unrest; these verbs are used of the effect of fear (shrinking back from fear), and, generally, the want of self-command; the Syr. otlahlah, to be terrified, obstupescere, confirms this primary conception, connecting itself with the R. להּ. Accordingly, he who shoots every possible death-bringing arrow, is thought of as one who is beside himself, one who is of confused mind, in which sense the passive forms of (Arab.) âlah and talah are actually used. Schultens' reference to (Arab.) lâh micare, according to which כמתלהלה must mean sicut ludicram micationem exercens (Bttcher: one who exerts himself; Malbim: one who scoffs, from התל), is to be rejected, because מתלהלה must be the direct opposite of משׂחק; and Ewald's comparison of (Arab.) wâh and akhkh, to be entangled, distorted, lâh, to be veiled, confounds together heterogeneous words. Regarding זקּים (from זנק), burning arrows, vid., under Isaiah 50:11. Death stands third, not as comprehensive (that which is deadly of every kind), but as a climax (yea, even death itself). The כּן of the principal sentence, correlate to כּ of the contiguous clause, has the Makkeph in our editions; but the laws of the metrical Makkeph require כּן אישׁ (with Munach), as it occurs e.g., in Cod. 1294. A man who gives vent to his malice against his neighbour, and then says: seest thou not that... (הלא, like Arab. âlâ), i.e., I am only jesting, I have only a joke with thee: he exhibits himself as being mad, who in blind rage scatters about him deadly arrows.

And death - Any instruments of death.