He poureth contempt upon princes - He has power to hurl them from their thrones, and to overwhelm them with disgrace.
And weakeneth the strength of the mighty - Margin, as in Hebrew "looseth the girdle of the strong." The Orientals wore loose flowing robes, which were secured by a girdle around the loins. When they labored, ran, or traveled, their robes were girded up. But this is common everywhere. Wrestlers, leapers, and runners, put a girdle around them, and are able thus to accomplish much more than they otherwise could. To loosen that, is to weaken them. So Job says that God had power to loosen the strength of the mighty. He here seems to labor for expressions, and varies the form of the image in every way to show the absolute control which God has over people, and the fact that his power is seen in the reverses of mankind. Lucretius has a passage strongly resembling this in the general sentiment:
Usque adeo res humanas vis abdita quaedam
Obterit; et pulchros fasces, saevasque secures,
Proculcare, atque ludibrio sibi habere, videtur.
Lib. v. 1232.
So from his awful shades, some Power unseen
O'erthrows all human greatness! Treads to dust
Rods, ensigns, crowns - the proudest pomps of state;
And laughs at all the mockery of mad!
Good.

He poureth contempt upon princes - נדיבים nedibim, "those of royal extraction;" widely different from the כהנים cohanim mentioned Job 12:19.
Weakeneth the strength of the mighty - אפיקים aphikim, the compact; the well-strung together; the nervous and sinewy. Perhaps there is a reference here to the crocodile, as the same term is applied, Job 40:13, to the compactness of his bones: and as רפה מזיח rippah meziach, which we translate weakeneth the strength, signifies more properly looseth the girdle, as the margin has properly rendered it, the reference seems still more pointed; for it is known that "the crocodile, from the shoulders to the extremity of the tail, is covered with large square scales, disposed like parallel girdles, fifty-two in number. In the middle of each girdle are four protuberances, which become higher as they approach the end of the tail, and compose four rows." See the quotation in Parkhurst, under the word אפק drow eh aphak. What is human strength against this? We may say as the Lord said, Job 40:19 : He that made him can make his sword to approach unto him. He alone can loose the girdles of this mighty one.

He poureth contempt upon princes,.... Not on good princes, such as rule in righteousness, and decree judgment and govern their subjects according to good laws, in a mild and gentle manner, and answer to their name of free, liberal, beneficent and munificent. These, as there is an honour due unto them, it is the will of God they should have it; much less are princes, in a figurative sense, meant, good men, the children of God, who are born of him the King of kings, and so princes in all the earth; but, in a literal sense, bad princes, that oppress their subjects, and rule them with rigour, and persecute good men; such as rose up against Christ, as Herod and Pontius Pilate; persecutors of the saints, as the Roman emperors, and the antichristian princes in the papacy; these God sometimes brings into contempt with their subjects, deposes them from their government, reduces them to a mean, abject, and servile state; or they die a shameful death, as Herod was eaten with worms, and many of the Heathen emperors died miserable deaths; and the vials of God's wrath will be poured out upon all the antichristian states, and their princes: pouring denotes the abundance of shame they are put to, as if they were clothed and covered with it, it being plentifully poured out like water, or as water was poured upon them, which is sometimes done by way of contempt, see Psalm 107:40;
and weakeneth the strength of the mighty; the strength of men, hale and robust, by sending one disease or another upon them, which takes it away from them; or by "the mighty" are meant men in power and authority; kings, as the Targum paraphrases it, mighty monarchs, whose strength lies in their wealth and riches, in their fortresses and powerful armies; all which God can deprive them of in an instant, and make them as weak as other men. Some render it, "and looseneth the girdle of the mighty" (b), the same as loosening the loins of kings, Isaiah 14:1; ungirding them, and taking away their power and authority from them, rendering them unfit for business, or unable to keep their posts and defend their kingdom.
(b) "et zonam potentium laxat", Tigurine version, Piscator, Beza, Schmidt; so Jarchi, Ben Gersom, Bar Tzemach, & Ben Melech.

Psalm 107:40 quotes, in its first clause, this verse and, in its second, Job 12:24.
weakeneth the strength--literally, "looseth the girdle"; Orientals wear flowing garments; when active strength is to be put forth, they gird up their garments with a girdle. Hence here--"He destroyeth their power" in the eyes of the people.