Killeth him - He wastes his strength and life in unsatisfied longings for something which he has not energy to gain. The wish to do great or good things may sometimes be taken for the deed, but if the hindrance is from a man's own sloth, it does but add to his condemnation.

The desire of the slothful killeth him - He desires to eat, drink, and be clothed: but as he does not labor, hence he dies with this desire in his heart, envying those who possess plenty through their labor and industry. Hence he is said to covet greedily all the day long, Proverbs 21:26, while the righteous, who has been laborious and diligent, has enough to eat, and some to spare.

The desire of the slothful (l) killeth him; for his hands refuse to labour.
(l) He thinks to live by wishing and desiring all things, but will make no effort to get anything.

The desire of the slothful killeth him,.... His desire after food and raiment, and riches; for because he cannot have what he desires, being unwilling to work for them, it frets and vexes him to death, or puts him upon unlawful methods to obtain them, which bring him to a shameful death; see Proverbs 13:4;
for his hands refuse to labour; when he is ordered by his superiors, or his wants are such as call for labour; and he seems to be willing and desirous of it, necessity obliging to it, yet he cannot bring his hands to it; these do in effect say, as Aben Ezra observes, Thou shall not do it. Maimonides says this is to be understood of sloth in seeking wisdom (h).
(h) Moreh Nevochim, par. 1. c. 34. p. 47.

Here is the misery of the slothful; their hands refuse to labour in an honest calling, by which they might get an honest livelihood; yet their hearts cease not to covet riches, pleasures, and honours, which cannot be obtained without labour. But the righteous and industrious have their desires satisfied.

desire--that is, of ease and idleness brings him to starvation.

25 The desire of the slothful killeth him;
For his hands refuse to be active.
The desire of the עצל, Hitzig remarks, goes out first after meat and drink; and when it takes this direction, as hunger, it kills him indeed. But in this case it is not the desire that kills him, but the impossibility of satisfying it. The meaning is simply: the inordinate desire after rest and pleasure kills the slothful; for this always seeking only enjoyment and idleness brings him at last to ruin. תּאוה means here, as in Kibroth ha-tava, Numbers 11:34, inordinate longing after enjoyments. The proverb is connected by almost all interpreters (also Ewald, Bertheau, Hitzig, Elster, Zckler) as a tetrastich with Proverbs 21:25 : he (the slothful) always eagerly desires, but the righteous giveth and spareth not. But (1) although צדּיק, since it designates one who is faithful to duty, might be used particularly of the industrious (cf. Proverbs 15:19), yet would there be wanting in 26a ואין, Proverbs 13:4, cf. Proverbs 20:4, necessary for the formation of the contrast; (2) this older Book of Proverbs consists of pure distichs; the only tristich, Proverbs 19:7, appears as the consequence of a mutilation from the lxx. Thus the pretended tetrastich before us is only apparently such.

Killeth - Torments him to death, while he passionately desires what he sees, he shall not enjoy, and will not take pains to procure.