I will cut off the inhabitant from Ashdod, And him who holds the scepter from Ashkelon; And I will turn my hand against Ekron; And the remnant of the Philistines will perish," says the Lord Yahweh.
"The remnant of the Philistines," as used by Amos here cannot possibly mean that "all of his prophecy (!) had already occurred, and that all of these grim warnings pertained only to a small remnant yet in the land. No!  "Remnant," as used here, means, "the rest of Philistia not already specifically mentioned in the prophecy."