דברי הימים א א:יב פירוש: רש״י

Pathrusim Pathrusim of the sea; Casluhim, Casluhim of the sea; Philistines, Philistines of the sea.

from whom the Philistines and the Caphtorim were descended The Pathrusim and the Casluhim would switch wives with each other, and from them were descended the Philistines (and the Caphtorim).