John Calvin Commentary Jeremiah 47:4

"because of the day that cometh to destroy all the Philistines, to cut off from Tyre and Sidon every helper that remaineth: for Jehovah will destroy the Philistines, the remnant of the isle of Caphtor." — Jeremiah 47:4 (ASV)

Jeremiah shows now more clearly, and without a figure, his meaning: that destruction would come on the Philistines when their time was completed. He mentions Tyre and Sidon, neighboring cities, and formerly under their own jurisdiction. But Tyre in the time of Isaiah had its own king; yet afterwards, in the time of Alexander the Great, the city was free, as is well known. These, however, were cities of Palestine, and the people then called Philistines were contiguous to these cities, so that the Prophet rightly includes them, as it were, in the same bundle. Coming, he says, is the day to destroy all the Philistines, and also to cut off the most opulent cities, even Tyre and Sidon.

Sidon was more ancient than Tyre, but the daughter devoured the mother, according to the common proverb. For Tyre in time flourished, and Sidon became almost forsaken. It, however, always retained a name and also some wealth on account of its commodious harbor. But Tyre was an island in the time of Alexander the Great and was therefore more commodious for ships, as it had many harbors. The Prophet connects them both together because they then formed a part of the land of the Philistines. There is no doubt that the destruction was especially denounced on these cities so that the Jews might know that nothing would be safe throughout the whole land, inasmuch as these cities, the defenses, as it were, of the whole country, were destined to perish.

He further adds that, because of the day which is coming against all the helping remnants, for Jehovah will destroy, that is, he will destroy the Philistines, who are the remnants (it is indeed another word, but means the same) of the island of Caphtor. He confirms here the same thing in other words: that God’s hand would be on these cities and the whole land, though external aids might come. These he calls all the remnants of courage, or auxiliaries. Though they might have many friends alive, ready to bring them help, yet the Lord would demolish them all, as it follows, for Jehovah will destroy the Philistines, the remnants of the island of Caphtor.

By the island of Caphtor he no doubt means Palestine; but it is doubtful for what reason the Hebrews called the Cappadocians Caphtorim. As it is hardly credible that those who inhabited this land had come from such a distant country, interpreters have supposed that others, and not Cappadocians, are here called Caphtorim. Yet Moses intimates (Deuteronomy 2:23) that those who inhabited the land from Gaza to Jordan were not natives—that is, were not born in those places—but that they were a wandering people, for he says that

The Caphtorim went forth and dwelt there
in the place of the natives.

We may hence conclude that the Caphtorim were foreigners who, wandering from their own country, sought a habitation elsewhere and took possession of this land. Whether they were Cappadocians, I leave undecided; nor should we toil much on a subject of this kind. But as the Caphtorim had emigrated into Palestine, Jeremiah calls that region the remnants of the island of Caphtor.