John Gill Bible Commentary

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 Rom 11:7; see Mat 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 Deu 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, Rev 1:7. The apostle renders the words "bow down their back alway"; See Gill on Rom 11:10.