Because of the day that cometh to spoil - “Because” the day has come “to devastate.”
The Philistines are called Tyre’s remaining (i. e., last) helper, because all besides who could have assisted her have already succumbed to the Chaldaean power. The judgment upon Philistia was in connection with that upon Tyre, and it was fulfilled by expeditions sent out by Nebuchadnezzar under him lieutenants to ravage the country and supply his main army with provisions.
The country of Caphtor - The coastland of Caphtor. The Philistines came from the coast of the Egyptian Delta, and are called “a remnant” because they had been greatly reduced in numbers, partly by the long war of Psammetichus against Ashdod, partly by the capture of Gaza Jeremiah 47:1, and partly by Assyrian invasions.