An evil man seeketh only rebellion: therefore a cruel messenger shall be sent against him.
An evil (man) seeketh only rebellion - so the Septuagint and Arabic. But the Chaldaic and Syriac take "rebellion" as the abstract for the concrete, and make it nominative. 'A rebel seeketh only evil,' notwithstanding a "hundred stripes" being inflicted on him (Proverbs 17:10).
Therefore a cruel messenger shall be sent against him - the executioner of the king's wrath. So the King of kings "casts upon" rebels against him "the fierceness of His anger ... by sending evil angels among them" (Psalms 78:49).