He shall cut off the spirit of princes: he is fearful to the kings of the earth.
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Augustine of Hippo
13. To whom shall they offer gifts? "To Him terrible, and to Him that taketh away the spirit of princes" (ver. 12). For the spirits of princes are proud spirits. They then are not His Spirits; for if they know anything, their own they will it to be, not public; but, that which setteth Himself forth as equal toward all men, that setteth Himself in the midst, in order that all men may take as much as they can, whatever they can; not of what is any man's, but of what is God's, and therefore of their own because they have become His. Therefore they must needs be humble: they have lost their own spirit, and they have the Spirit of God. ...For if thou shalt have confessed thyself dust, God out of dust doth make man. All they that are in the circuit of Him do offer gifts. All humble men do confess to Him, and do adore Him. "To Him terrible they offer gifts." Whence to Him terrible exult ye with trembling: "and to Him that taketh away the spirit of princes:" that is, that taketh away the haugh...
Away. Hebrew, "he will cut off "(Montanus) like grapes: which means rather to destroy, than to bereave of counsel, Isaias xix. 13. This might be written after Sennacherib was slain, 4 Kings xix. 37. (Calmet)
God is terrible, and will demand an account even of princes, respecting vows and other good works. Great discretion is therefore requisite. (Worthington)