Therefore Yahweh will cut off from Israel head and tail, palm branch and reed, in one day.
The Lord sends warning before He wounds; He spoke through His prophets, but Israel refused to hear. Those willingly ignorant of God's wrath revealed against sin shall be made to know it by feeling it. The people's insolence defies justice itself: they say, let God do His worst, we will hold our ground, rebuild stronger than before. They will not repent at the word, so they shall learn through the blow.
AI summary
Commenting on Isaiah 9:8-21
Therefore the Lord will cut off from Israel head and tail,.... The former of these is afterwards interpreted of "the ancient and honourable", men in high places, civil magistrates, judges, governors, and elders of the people, the king as supreme, and all subordinate officers; and so the Targum, "the Lord will destroy from Israel the prince and the ruler;'' and the latter is interpreted of the false prophet.
14. Therefore the Lord will cut off from Israel. He intimates that God’s vengeance will be universal, and will involve all ranks; for the whole nation was corrupted, and the contagion had spread over the whole country, to such an extent that no part was left whole or sound.