Because he covereth his face with his fatness - That is, he not only stretches out his hand against God Job 15:25 and rushes upon him as an armed foe Job 15:26, but he gives himself up to a life of luxury, gluttony, and licentiousness; and therefore, these calamities must come upon him. This is designed to be a description of a luxurious and licentious person - a man who is an enemy of God, and who, therefore, must incur his displeasure.
And maketh collops of fat - Like an ox that is fattened. The word collop properly means "a small slice of meat, a piece of flesh" (Webster), but here it means a thick piece, or a mass. The word is used in this sense in New England. The sense is, that he becomes excessively fat and gross - as they usually do who live in sensual indulgence and who forget God.

Because he covereth his face - He has lived in luxury and excess; and like a man overloaded with flesh, he cannot defend himself against the strong gripe of his adversary. The Arabic, for maketh collops of fat on his flanks, has (Arabic) He lays the Pleiades upon the Hyades, or, He places Surreea upon aiyuk, a proverbial expression for, His ambition is boundless; He aspires as high as heaven; His head touches the stars; or, is like the giants of old, who were fabled to have attempted to scale heaven by placing one high mountain upon another: -
Ter sunt conati imponere Pelio Ossam
Scilicet, atque Ossae frondosum involvere Olympum
Ter Pater extructos disjecit fulmine montes.
Virg. Geor. i., ver. 281.
"With mountains piled on mountains, thrice they strove
To scale the steepy battlements of Jove;
And thrice his lightning and red thunder play'd,
And their demolished works in ruins laid."
Dryden.
To the lust of power and the schemes of ambition there are no bounds; but see the end of such persons: the haughty spirit precedes a fall; their palaces become desolate; and their heaven is reduced to a chaos.

Because he covereth his face with (q) his fatness, and maketh collops of fat on [his] flanks.
(q) That is, he was so puffed up with prosperity and abundance for all things, that he forgave God: noting that Job in his happiness did not have the true fear of God.

Because he covereth his face with his fatness,.... He has no fear of God, nor shame for his sin; he blushes not to rise up against God in the manner he does, because his eyes stand out with fatness; or rather his face is covered with it, that is, he abounds in riches, he enjoys great prosperity, a large affluence of all good things; and this makes him haughty and imperious, neither to fear God, nor regard man like Jeshurun, who, when he "waxed fat, was grown thick, and covered with fatness, kicked" against God, and his providences, sinned and rebelled against him; "forsook God which made him, and lightly esteemed the Rock of his salvation", Deuteronomy 32:15; and to the same purpose is the following clause:
and maketh collops of fat in his flanks; a description of a very fat man, and one that pampers the flesh, and indulges himself in eating and drinking; and, figuratively, of one that abounds in the good things of this world, and which make him vain and proud, and lead him on to commit sin in a bold and daring way, promising himself impunity in it, but without any just ground for it, as the following verses show; perhaps some respect may be had to Job's children feasting with one another in their prosperity, which led on to sin, and issued in their ruin, as Eliphaz would suggest.

The well-nourished body of the rebel is the sign of his prosperity.
collops--masses of fat. He pampers and fattens himself with sensual indulgences; hence his rebellion against God (Deuteronomy 32:15; 1-Samuel 2:29).

Because - This is mentioned as the reason of his insolent carriage towards God, because he was fat, rich, potent, and successful, as that expression signifies, Deuteronomy 32:15; Psalm 78:31; Jeremiah 46:21. His great prosperity made him proud and secure, and regardless of God and men. Fat - His only care is to pamper himself.