Let their eyes be darkened, that they may not see. The Psalmist here refers chiefly to two powers of the body, those of the eyes and of the loins; and I have no hesitation in considering his language as a prayer that God would deprive his enemies of reason and understanding, and at the same time enfeeble their strength, that they might be altogether unfitted for exerting themselves in any way. We know how indispensable it is, in order to the doing of any thing aright, that counsel go before to give light, and that there should also be added the power of putting what is purposed into execution. The curse here expressed impends over the heads of all the enemies of the Church; and, therefore, we have no reason to be terrified at the malice or fury of the wicked. God, whenever he pleases, can strike them suddenly with blindness, that they may see nothing, and by breaking their loins, [1] lay them prostrate in shame and confusion.

Footnotes

1 - The loins are the seat of strength in every animal; and hence the prayer, "Make their loins continually to tremble," is just a prayer that their strength might be impaired, or entirely taken away.

Let their eyes be darkened - See the notes at Romans 11:10.
And make their loins continually to shake - As under a heavy burden. The apostle Romans 11:10 varies the language, but retains the idea: "and bow down their back alway."

Let their eyes be darkened, that they see not; and make their (s) loins continually to shake.
(s) Take both judgment and power from them, (Acts 1:20).

Let their eyes be darkened, that they see not,.... Not literally, the eyes of their bodies; but figuratively, the eyes of their understanding; which were so darkened, and they given up to such judicial blindness, that they could not discern the signs of the times that the Messiah must be come, Daniel's weeks being up; could not see any glory, excellency, and comeliness in Christ; could not see the evidence of the Messiahship of Jesus in the miracles he wrought; nor in the prophecies of the Old Testament fulfilled in him: that book was a sealed book unto them; the Gospel, and the doctrines of it, were hid from them, even from the wise and prudent among them; yea, also those things which belonged to their temporal peace; they were so blinded and infatuated, they could not see what was for their outward good and happiness: and, in proof of this their blindness, the words are cited by the apostle in Romans 11:7; see Matthew 16:3;
and make their loins continually to shake; weaken their loins, in which a man's strength lies, that they may not be able to rise up against their enemies; and that they might not be able to flee and escape from them; see Deuteronomy 33:11; or fill them with horror, dread, and trembling, as they will be when Christ shall come in the clouds of heaven; and they shall see him whom they have pierced, Revelation 1:7. The apostle renders the words "bow down their back alway"; See Gill on Romans 11:10.

continually to shake--literally, "to swerve" or bend in weakness.

Eyes - Not the eyes of their bodies, but of their minds: as they that shut their eyes and will not see, so they shall be judicially blinded. To shake - To take away their strength.