Amos 1:8

and I will cut off the inhabitant from Ashdod, to make the city desolate, and him that holdeth the scepter from Ashkelon, the ruler of this city-state with his people, and I will turn Mine hand against Ekron, so that four of the five city-states are expressly mentioned, the fifth, which bore the name Gath, being omitted because it was not essential to name them all; and the remnant of the Philistines shall perish, saith the Lord God, the prophecy finding its fulfillment in the repeated conquest of Philistia by the great world-powers, so that it did not retain its existence for any length of time.