Bridges on Proverbs 30:17
Charles Bridges on Proverbs 30:17

17.  The eye that mocketh at his father, and despiseth to obey his mother, the ravens of the valley shall pick it out, and the young eagles shall eat it. {the valley: or, the brook}
Agur here returns to the first generation — the unnatural despisers of their parents. (Verse 11.) He had before described their character. Now he links it with the punishment. Observe the guilt only of a scornful look, or the mocking eye, when perhaps not a word is spoken. Certainly if the fifth commandment is “the first with promise” (Ephesians 6:2), it is also the first with judgment. No commandment in the breach of it is visited with more tremendous threatenings. What a picture is here given of infamy! Perhaps the case of Absalom furnishes the most striking illustration — a self-willed youth or rebel against his father and his sovereign, made a spectacle of shame before his people! the vengeance of God inflicting the punishment which was due at the bar of human justice! (2 Samuel 18:17.) But we may observe a more general illustration of the frightful picture. How many confessions on the scaffold have borne testimony that the first step towards the untimely end was contempt of parental authority and restraint! The bodies of such criminals were deprived of the rites of burial; exposed either on the gallows, or cast out into the valley, as meat for the fowls of the air.† Thus the eye, that hath scornfully mocked his father, became the choice morsel of the eagle or the raven of the valley.†
But even where there is no such literal fulfillment, the curse is not the less sure. Seldom do we see the disobedient rebels prospering, and blessed in their own children. Retributive justice visits them late but certain; and the poignant anguish of many a disappointed hope, and many an arrow shot from their own bow, may bear to them the message of their chastising Father — “Thine own iniquities shall correct thee, and thy backslidings shall reprove thee.” (Jeremiah 2:19.)